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Fisdap Cardiology Review (Paramedic)-with 100% verified solutions 2024-2025, Exams of Nursing

Fisdap Cardiology Review (Paramedic)-with 100% verified solutions 2024-2025

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Download Fisdap Cardiology Review (Paramedic)-with 100% verified solutions 2024-2025 and more Exams Nursing in PDF only on Docsity! Fisdap Cardiology Review (Paramedic)-with 100% verified solutions 2024-2025 You respond to a residence for a 68-year-old male with nausea, vomiting, and blurred vision. As you are assessing him, he tells you that he has congestive heart failure and atrial fibrillation, and takes numerous medications. The cardiac monitor reveals atrial fibrillation with a ventricular rate of 50 beats/min. Which of the following medications is MOST likely responsible for this patient's clinical presentation? Digoxin. This patient has classic signs of digitalis toxicity. Digoxin is commonly prescribed to patients with congestive heart failure and atrial fibrillation (A-Fib) or atrial flutter (A-Flutter). Its positive inotropic effects increase cardiac contractility and maintain cardiac output, while its negative chronotropic effects control the ventricular rate of the A-Fib or A-Flutter. Digitalis preparations (ie, Lanoxin, Digoxin) have a narrow therapeutic index—that is, there is a fine line between a therapeutic and toxic dose. You should suspect digitalis toxicity in any patient who takes Digoxin or Lanoxin and presents with complaints such as nausea, vomiting, abdominal pain, anorexia, or blurred/yellow vision. Additionally, virtually any cardiac dysrhythmia can be caused by the toxic effects of digitalis. Treatment involves the administration of Digibind, which is given at the hospital. Which of the following is an absolute contraindication for fibrinolytic therapy? Subdural hematoma 3 years ago. According to current emergency cardiac care (ECC) guidelines, absolute contraindications for fibrinolytic therapy include ANY prior intracranial hemorrhage (ie, subdural, epidural, intracerebral hematoma); known structural cerebrovascular lesion (ie, arteriovenous malformation); known malignant intracranial tumor (primary or metastatic); ischemic stroke within the past 3 months, EXCEPT for acute ischemic stroke within the past 3 hours; suspected aortic dissection; active bleeding or bleeding disorders (except menses); and significant closed head trauma or facial trauma within the past 3 months. Relative contraindications (eg, the physician may deem fibrinolytic therapy appropriate under certain circumstances) include, a history of chronic, severe, poorly-controlled hypertension; severe uncontrolled hypertension on presentation (SBP > 180 mm Hg or DBP > 110 mm Hg); ischemic stroke greater than 3 months ago; dementia; traumatic or prolonged (> 10 minutes) CPR or major surgery within the past 3 weeks; recent (within 2 to 4 weeks) internal bleeding; noncompressible vascular punctures; pregnancy; prior exposure (> 5 days ago) or prior allergic reaction to streptokinase or anistreplase; active peptic ulcer; and current use of anticoagulants (ie, Coumadin). A middle-aged man presents with chest discomfort, shortness of breath, and nausea. You give him supplemental oxygen and continue your assessment. As your partner is attaching the ECG leads, you should: Administer up to 325 mg of aspirin. Since oxygen has already been administered to this patient and your partner is attaching the ECG leads, you should administer aspirin (160 to 325 mg, non-enteric-coated). Early administration of aspirin has clearly been shown to reduce mortality and morbidity in patients experiencing an acute coronary syndrome (ACS). After establishing vascular access, you should assess his vital signs and then administer 0.4 mg of nitroglycerin (up to 3 doses, 5 minutes apart), provided that his systolic BP is greater than 90 mm Hg. If 3 doses of nitroglycerin fail to completely relieve his chest discomfort, consider administering 2 to 4 mg of morphine IV, provided that his systolic BP remains above 90 mm Hg. Which of the following ECG lead configurations is correct? To assess lead II, place the negative lead on the right arm and the positive lead on the left leg. According to the Einthoven triangle, lead I is assessed by placing the negative (white) lead on the right arm and the positive (red) lead on the left arm. Lead II is assessed by placing the negative lead on the right arm and the positive lead on the left leg. Lead III is assessed by placing the negative lead on the left arm and the positive lead on the left leg. A 61-year-old male presents with chest pressure that woke him up from his nap 30 minutes ago. He is diaphoretic, anxious, and rates his pain as an an 8 over 10. His past medical history is significant for hypertension, type II diabetes, and coronary stent placement 2 months ago. He takes lisinopril, Plavix, and Glucophage, and is wearing a medical alert bracelet following cardiac rhythms would MOST likely be seen on the cardiac monitor? Uncontrolled atrial fibrillation. Of the cardiac rhythms listed, atrial fibrillation (A-Fib) is the only one that is irregularly irregular. In fact, A-Fib is never seen as a regular rhythm. At a rate of less than 100 beats/min, A-Fib is said to be controlled. Uncontrolled A-Fib, or A-Fib with a rapid ventricular rate (RVR), occurs when the ventricular rate exceeds 100 beats/min. Second-degree AV block type I has a pattern that is regularly irregular; the P-R interval progressively lengthens until a P wave is blocked. Ventricular tachycardia (V-Tach) and supraventricular tachycardia (SVT) are typically regular rhythms. What is the correct initial dose and rate of administration of amiodarone for a patient with refractory ventricular fibrillation? 300 mg via rapid IV or IO push. The correct initial dose and rate of administration of amiodarone for a patient with refractory ventricular fibrillation or pulseless ventricular tachycardia is 300 mg rapid IV or IO push. You may repeat amiodarone one time in 5 minutes at a dose of 150 mg rapid IV or IO push. For patients with hemodynamically stable narrow or wide-complex tachycardias, the correct dose and rate of administration for amiodarone is 150 mg given over 10 minutes. We have an expert-written solution to this problem! The main purpose of listening to heart sounds is to: Determine if the cardiac valves are functioning properly. In general patient assessment, the main purpose of listening to heart sounds is to identify the "lub-dub" that indicates the cardiac valves are functioning properly. S1 (lub) occurs near the beginning of ventricular contraction, when the tricuspid and mitral valves close. S2 (dub) occurs near the end of the ventricular contraction, when the pulmonary and aortic valves close. Although cardiac rate and regularity can be assessed by listening to heart sounds (apical pulse), the quality of the heartbeat can only be assessed by palpating the pulse. The point of maximal impulse (PMI)—also called the apical thrust—is not heard, but rather seen. The PMI, which is normally located on the left anterior part of the chest in the midclavicular line at the fifth intercostal space, occurs when the heart's apex rotates forward with systole and gently beats against the chest wall, producing a visible pulsation. Which of the following represents the correct adult dosing regimen for adenosine? 6 mg, followed by 12 mg in 2 minutes if needed. According to the 2010 guidelines for CPR and emergency cardiac care (ECC), the correct dosing regimen of adenosine for a hemodynamically stable patient with a narrow-complex tachycardia is 6 mg via rapid (over 1 to 3 seconds) IV push. If needed, adenosine can be repeated in 1 to 2 minutes in a dose of 12 mg rapid IV push. You should interpret the following cardiac rhythm as: Atrial flutter with a fixed block. Because of the typical "sawtooth" flutter (F) waves, this rhythm is interpreted as atrial flutter (A-Flutter). The block is fixed in that the ratio of F waves to QRS complexes is consistent (2:1). A-Flutter with a variable block occurs when the ratio of F waves to QRS complexes is different. Atrial fibrillation (A-Fib) is characterized by an irregularly irregular rhythm with no identifiable P waves. A type II second-degree AV block is characterized by a rhythm in which some P waves are blocked (eg, they are not followed by QRS complexes). Cardioversion involves delivering a shock that is synchronized to occur during the: R wave. Cardioversion involves delivering a shock that is synchronized to occur during the R wave, which is when the heart is absolutely refractory. This prevents the shock from occurring during the relative refractory period (the downslope of the T wave). Depolarization that occurs during the relative refractory period may induce a non-perfusing ventricular dysrhythmia, such as pulseless V-Tach or V-Fib. Synchronized cardioversion is indicated for patients with supraventricular or ventricular tachycardia who have a pulse, but are hemodynamically unstable. Which of the following electrolytes moves slowly into the cardiac cell and maintains the depolarized state of the cell membrane? Calcium. The process of depolarization begins as sodium ions rush into the cell. At the same time, calcium ions enter the cell—albeit more slowly and through specialized channels—to help maintain the depolarized state of the cell membrane and to supply calcium ions for contraction of cardiac muscle tissue. During repolarization, the sodium and calcium channels close, thus stopping the rapid influx of these ions. Then, special potassium channels open, allowing potassium ions to rapidly exit the cell. This helps restore the inside of the cell to its negative charge; the proper electrolyte distribution is then reestablished by pumping sodium ions out of the cell and potassium ions back in. After the potassium channels close, the sodium-potassium pump helps move sodium and potassium ions back to their respective locations. For every three sodium ions the pump moves out of the cell, it moves two potassium ions into the cell, thereby maintaining the polarity of the cell membrane Which of the following cardiac rhythms is associated with bradycardia, and is characterized by regular R-R intervals and a greater ratio of P waves to QRS complexes? After performing synchronized cardioversion on an unstable patient with a wide-complex tachycardia, you look at the monitor and see coarse ventricular fibrillation. The patient is unresponsive, apneic, and pulseless. You should: Start CPR, ensure the synchronize mode is off, and defibrillate. If a patient develops ventricular fibrillation (V-Fib) or pulseless ventricular tachycardia (V-Tach) following synchronized cardioversion, immediately begin CPR (even if it's just for a short period of time), ensure that the monitor/defibrillator is not in synchronize mode, and defibrillate as soon as possible. CPR should be ongoing as the defibrillator is charging in order to avoid unnecessary delays in performing chest compressions. The synchronize mode must be turned off prior to defibrillation or the device will not deliver a shock; this is because there are no R waves to synchronize with in V-Fib. Vascular access (IV or IO), advanced airway management, and pharmacologic therapy should be performed during the 2-minute cycles of CPR; they are not an immediate priority during early cardiac arrest. We have an expert-written solution to this problem! A 70-year-old man presents with an acute onset of confusion, slurred speech, and left side weakness. According to his daughter, he has high blood pressure and has had several "small strokes" over the past 6 months. Your partner applies supplemental oxygen; assesses his vital signs, which are stable; and assesses his blood glucose level, which reads 35 mg/dL. You attempt to perform the Cincinnati Prehospital Stroke test, but the patient is unable to understand your instructions. After establishing IV access, you should: Administer 50% dextrose, monitor his cardiac rhythm, protect his impaired extremities, and transport. This patient's clinical presentation and his history of hypertension and transient ischemic attacks (TIAs) suggest acute ischemic stroke. However, his blood glucose level (BGL) is significantly low and must be treated. Untreated hypoglycemia may cause irreversible brain damage or death. Appropriate treatment for this patient involves administering 50% dextrose (consider giving 12.5 g) and then reassessing his BGL to determine the need for additional glucose. Because the patient is confused, and because some patients with acute ischemic stroke lose protective airway reflexes, oral glucose should be avoided. He may not be able to swallow it, which may result in aspiration. Further treatment includes protecting his impaired extremities from injury, monitoring his cardiac rhythm, and transporting him to the hospital. Notify the receiving facility early. Aspirin should be avoided in the prehospital setting for patients with signs and symptoms of a stroke. A CT scan of the head must be performed first to rule out intracranial hemorrhage. Which of the following clinical presentations is MOST consistent with an acute ischemic stroke involving the left cerebral hemisphere? Dysarthria, confusion, right side hemiparesis, left side facial droop. Acute ischemic strokes represent approximately 75% of all strokes. Each cerebral hemisphere controls functions on the contralateral (opposite) side of the body; therefore, sensory and motor deficits (ie, hemiparesis, hemiparalysis) are observed on the side of the body opposite the stroke. However, because the facial nerves do not decussate (cross as they leave the cerebral cortex, move through the brainstem, and arrive at the spinal cord), facial droop is typically observed on the ipsilateral (same) side as the stroke. Pupillary changes, if present, will also occur on the same side as the stroke because of optic nerve crossover in the brain. Other common signs of acute ischemic stroke include dysarthria (slurred speech), dysphasia (difficulty speaking or understanding), aphasia (inability to speak or understand), and mental status changes. In contrast to acute ischemic stroke, acute hemorrhagic stroke (caused by a ruptured cerebral artery) typically presents with more ominous signs, which include a sudden, severe headache that is followed by a rapid decline in level of consciousness. Because bleeding is occurring within the brain, intracranial pressure increases, resulting in signs such as decorticate (flexor) or decerebrate (extensor) posturing, asymmetric or bilaterally dilated pupils, and Cushing's triad (hypertension, bradycardia, abnormal respiratory pattern). A 27-year-old female complains of palpitations. The cardiac monitor reveals a narrow-complex tachycardia at 180/min. She denies any other symptoms, and states that this has happened to her before, but it typically resolves on its own. Her blood pressure is 126/66 mm Hg, pulse is 180 beats/min, and respirations are 16 breaths/min. After attempting vagal maneuvers and giving two doses of adenosine, her cardiac rhythm and vital signs remain unchanged. You should: Transport at once, reassess her frequently, and perform synchronized cardioversion if necessary. Although the patient is in supraventricular tachycardia (SVT), she remains stable following your initial efforts to slow her heart rate with vagal maneuvers and adenosine. Her failure to respond to initial treatment does not automatically make her unstable. Simply transport her, closely monitor her en route, and be prepared to cardiovert her if she does become unstable (ie, hypotension, altered mental status, chest pain). Unless specified in your local protocols, pharmacologic therapy beyond adenosine (ie, calcium channel blockers, amiodarone) is typically not indicated in the field for stable patients with SVT, although these medications may be given in the emergency department. However, if your protocols or medical control call for the administration of diltiazem (Cardizem), the initial dose is 0.25 mg/kg. You should interpret the following cardiac rhythm as: Third-degree AV block. The rhythm is regular, with a ventricular rate of approximately 40 to 50 beats/min. It has wide (greater than 120 ms [0.12 sec]) QRS complexes and more P waves than QRS complexes. Because there is no relationship between any one P wave to a given QRS complex, this is a third-degree AV block, also called complete heart block. First-degree AV block is characterized by P-R intervals that exceed 200 ms (0.20 seconds [5 small boxes]), although there is a consistent 1:1 P-to-QRS ratio; unless ectopic compexes are present, it is usually a regular rhythm. Second-degree AV block type I is characterized by P-R intervals that progressively lengthen until a P wave is blocked (not followed by a QRS complex); it is an irregular rhythm. Second-degree AV block type II, which may be regular or Although the patient's heart rate is slow, he is hemodyamically stable; therefore, pharmacological or electrical intervention aimed at increasing his heart rate is not indicated at this point. Provide supportive care (ie, oxygen as needed, IV set to a KVO/TKO rate) and transport him to the hospital. Consider administering an antiemetic drug, such as ondansetron (Zofran) or promethazine (Phenergan). If his clinical status deteriorates (ie, chest pain, dyspnea, altered mental status, hypotension), atropine sulfate (0.5 mg) or transcutaneous cardiac pacing (TCP) will be necessary. IV fluid boluses are not indicated at this point because there is no evidence of hypovolemia. What are the therapeutic effects of aspirin when given to patients experiencing an acute coronary syndrome? Prevents platelet aggregation. Aspirin (acetylsalicylic acid [ASA]) blocks the formation of thromboxane A2, thus minimizing local coronary vasoconstriction and preventing platelet aggregation. Therefore, aspirin helps prevent an existing clot from getting any larger. Aspirin has clearly been shown to reduce mortality and morbidity from acute coronary syndrome (ACS), and should be given as soon as possible. Examples of blood thinners (anticoagulants) include warfarin sodium (Coumadin) and heparin. Aspirin is not an anticoagulant, nor does it dilate the coronary arteries; nitroglycerin (NTG) does this. What are the therapeutic effects of morphine sulfate when administered to a patient with cardiogenic pulmonary edema? Increased venous capacitance and decreased preload. In patients with cardiogenic pulmonary edema (ie, congestive heart failure [CHF]), morphine sulfate causes systemic pooling of blood, which increases venous capacitance and decreases preload (the volume of blood returned to the heart). The net effect is to minimize the volume of fluid that accumulates in the lungs. Note that morphine is not a diuretic and will not remove fluid from the body. This is accomplished by administering furosemide (Lasix), which may be considered for patients with CHF and pulmonary edema. We have an expert-written solution to this problem! Occlusion of the right coronary artery would MOST likely result in: Sinoatrial node failure. The sinoatrial (SA) node is the dominant cardiac pacemaker; it sets the inherent rate at which the heart beats. The SA node receives blood from the right coronary artery (RCA); therefore, if the RCA is occluded (ie, acute myocardial infarction), the SA node will become ischemic and may cease functioning. If this occurs, the atrioventricular (AV) node would likely assume the role of the primary pacemaker, although at an inherently slower rate. If the SA node fails, the flow of electricity throughout the atria would likely suffer as well; this would result in a decrease in atrial kick— the volume of blood (about 20%) that is ejected from the atria to the ventricles (the other 80% fills the ventricles by gravity). Sudden cardiac arrest is more likely to occur following occlusion of the left main coronary artery. Ectopic ventricular complexes (eg, PVCs), although benign in many cases, may indicate irritability in the ventricles. Immediately after establishing a return of spontaneous circulation in a woman with ventricular fibrillation of short duration, you should: Assess her ventilatory status and treat accordingly. Your first action after establishing return of spontaneous circulation (ROSC) in a patient—regardless of his or her arrest rhythm and duration— is to assess the patient's ventilatory status. If the patient is not breathing or is breathing inadequately, provide ventilatory support. After assessing and managing airway and breathing, assess the patient's blood pressure and stabilize it if it is low. Airway and circulatory support are critical following ROSC; inadequate ventilation and/or hypotension following cardiac arrest may lead to a recurrence of cardiac arrest. Depending on your local protocols, IV amiodarone may be given following ROSC. After assessing and maintaining respiratory and circulatory functions, obtain a 12-lead ECG if time allows. If the patient remains comatose following ROSC, consider inducing therapeutic hypothermia. A 56-year-old man presents with the cardiac rhythm shown below. He complains of chest discomfort, shortness of breath, and is profusely diaphoretic. His blood pressure is 84/64 mm Hg and his radial pulses are barely palpable. You should: Consider sedation and perform cardioversion. Your patient has a narrow-complex tachycardia, probably supraventricular tachycardia (SVT). Furthermore, he is hemodynamically unstable as evidenced by his hypotension, respiratory distress, and chest discomfort. Heart rates greater than 150 beats/min often cause hemodynamic compromise because they impair ventricular filling and subsequent cardiac output. Patients with unstable tachycardias require synchronized cardioversion. For the patient with a regular narrow-complex tachycardia (ie, SVT), start with 50 to 100 joules. Consider sedating the patient prior to cardioversion only if doing so does not delay the procedure. If the initial cardioversion attempt is unsuccessful, repeat the cardioversion, increasing the energy setting in a stepwise fashion, and search for potentially reversible underlying causes. Defibrillation is indicated for patients with V-Fib and pulseless V-Tach. Transcutaneous cardiac pacing (TCP) is indicated for patients with hemodynamically unstable bradycardia. Amiodarone, in a dose of 150 mg over 10 minutes, is indicated for patients with stable narrow or wide-complex tachycardias. Which of the following interventions has the greatest impact on patient survival from sudden cardiac arrest? Early CPR and defibrillation. Early CPR and defibrillation are the two interventions that will have the greatest impact on patient survival from sudden cardiac arrest (SCA). Early, effective CPR maintains perfusion to the body's vital organs until defibrillation can be provided. The most common initial cardiac rhythm observed during SCA is ventricular fibrillation (V-Fib). Early defibrillation, in After determining that an adult patient is unresponsive and apneic, you should assess for a carotid pulse for at least 5 seconds but no more than 10 seconds. If the patient has a pulse, open the airway and provide rescue breathing. If the patient does not have a pulse, begin CPR (starting with chest compressions), then open the airway and give 2 rescue breaths. Assess the patient's cardiac rhythm as soon as a monitor/defibrillator is available. A clinically unstable patient presents with an irregular narrow-complex tachycardia at a rate of 170 per minute. What is the recommended initial energy setting for synchronized cardioversion? 120 to 200 joules. If a patient has a heart rate that is greater than 150 per minute, and he or she is clinically unstable because of the cardiac rhythm, synchronized cardioversion should be performed. The following initial energy settings are recommended by current emergency cardiac care (ECC) guidelines: narrow and regular, 50 to 100 joules (biphasic or monophasic); narrow and irregular, 120 to 200 joules biphasic (200 joules monophasic); wide and regular, 100 joules (biphasic or monophasic); wide and irregular, defibrillation dose (NOT synchronized). If the initial energy dose is unsuccessful, increase in a stepwise fashion. You are assessing a 50-year-old man with acute chest pressure, diaphoresis, and nausea. The 12-lead ECG tracing reveals 3-mm ST segment elevation in leads V3 through V6. This indicates: Anterolateral injury. Leads V1 and V2 view the interventricular septum. Leads V3 and V4 view the anterior wall of the left ventricle. Leads I, aVL, V5 and V6 view the lateral wall of the left ventricle. Leads II, III, and aVF view the inferior wall of the left ventricle. Myocardial ischemia manifests on the 12-lead ECG with ST segment depression and/or T-wave inversion, whereas myocardial injury manifests with ST segment elevation that is equal to or greater than 1-mm in two or more contiguous leads. Therefore, 3-mm ST segment elevation in leads V3 through V6 indicates injury to the anterior and lateral wall of the left ventricle (anterolateral injury). In addition to CPR, the recommended treatment sequence for an unresponsive, apneic, and pulseless patient with a regular, wide-complex cardiac rhythm at a rate of 40 beats/min includes: 1 mg of epinephrine every 3 to 5 minutes and treating reversible causes. Pulseless electrical activity (PEA) exists when an unresponsive, apneic, pulseless patient presents with a regular cardiac rhythm. Treatment for PEA includes immediate high-quality CPR with minimal interruptions, obtaining vascular access (IV or IO), 1 mg of epinephrine every 3 to 5 minutes, advanced airway management (ie, ET tube, multilumen or supraglottic airway), and assessing for and treating reversible causes (Hs and Ts). Vasopressin, in a one-time dose of 40 units, can be given to replace the first or second dose of epinephrine, but not both. There are insufficient data to recommend transcutaneous pacing (TCP) for patients with bradycardic PEA or asystole, and the routine use of calcium chloride during cardiac arrest is not recommended. An older man is suddenly awakened in the middle of the night, gasping for air. He is extremely restless and pale, and is coughing up blood. His clinical presentation is MOST consistent with: Left side heart failure. Waking up in the middle of the night with severe difficulty breathing (paroxysmal nocturnal dyspnea [PND]) and coughing up blood or blood- tinged sputum (hemoptysis) are consistent with left-sided heart failure and pulmonary edema. Right-sided heart failure typically does not present with respiratory distress; it commonly manifests with jugular venous distention and peripheral edema. Shortness of breath and hemoptysis are not consistent with a gastrointestinal (GI) bleed; signs of a GI bleed include abdominal pain, vomiting up blood (hematemesis), which may be bright red or have a coffee-ground appearance; dark, tarry stools (melena); or bright red blood in the stool (hematochezia). Because left- sided heart failure can be caused by other factors, such as a long history of poorly-controlled hypertension, angina may or may not be present. We have an expert-written solution to this problem! A 145-pound man requires a dopamine infusion at 15 µg/kg/min for severe hypotension. You have a premixed bag containing 800 mg of dopamine in 500 mL of normal saline. If you are using a microdrip administration set (60 gtts/mL), how many drops per minute should you deliver to achieve the required dose? 36. First, convert the patient's weight from pounds to kilograms: 145 ÷ 2.2 = 66 kg. Next, determine the desired dose: 15 µg/kg/min × 66 kg = 990 µg/min. The next step is to determine the concentration of dopamine on hand: 800 mg ÷ 500 mL = 1.6 mg/mL (1,600 µg/mL [1.6 × 1,000 = 1,600]). Now, you must determine the number of mL to be delivered per minute: 990 µg/min [desired dose] ÷ 1,600 µg/mL [concentration on hand] = 0.6 mL/min. The final step is to determine the number of drops per minute that you must set your IV flow rate at: 0.6 mL/min × 60 gtts/mL (drop factor of the microdrip) ÷ 1 (total infusion time in minutes) = 36 gtts/min. We have an expert-written solution to this problem! A 35-year-old female experienced a syncopal episode shortly after complaining of palpitations. She was reportedly unconscious for less than 10 seconds. Upon your arrival, she is conscious and alert, denies any injuries, and states that she feels fine. She further denies any significant medical history. Her vital signs are stable and the cardiac monitor reveals a sinus rhythm with frequent premature atrial complexes. On the basis of this information, what MOST likely caused her syncopal episode? Paroxysmal supraventricular tachycardia. A right ventricular infarction (RVI) should be suspected when a patient presents with ECG changes indicative of an inferior wall injury pattern (equal to or greater than 1-mm ST elevation in leads II, III, and aVF; reciprocol ST depression and T wave inversion in leads I and aVL) AND has equal to or greater than 1-mm ST elevation in lead V4R when a right-sided 12-lead ECG is obtained. Patients experiencing an RVI are preload dependent and often present with hypotension; therefore, vasodilators (eg, nitroglycerin, morphine) should be avoided. Instead, IV fluid boluses should be given to maintain adequate perfusion. Other signs of an RVI include jugular venous distention and peripheral edema. Pulmonary edema and coughing up blood (hemoptysis) are indicative of left ventricular failure. A 44-year-old man presents with the rhythm shown below. He complains of nausea, but denies vomiting. He is conscious and alert with a BP of 122/62 mm Hg, a pulse rate of 98 beats/min, and respirations of 16 breaths/min and unlabored. Treatment for this patient would MOST likely include: Ondansetron, 4 mg. Unless associated with a fast rate (> 100 beats/min) and hemodynamic compromise (eg, hypotension, altered mental status, pulmonary edema), treatment for atrial flutter is usually not necessary in the prehospital setting. Administer supplemental oxygen if indicated, transport, and monitor the patient's hemodynamic status en route. For this patient, you should treat his nausea with an antiemetic, such as ondansetron (Zofran), 4 mg; or promethazine (Phenergan), 12.5 to 25 mg. When assessing a patient with suspected cardiac-related chest pain, which of the following questions would be MOST appropriate to ask? Can you describe the quality of the pain? Patient assessment involves simple questioning techniques. You should ask open-ended questions, whenever possible; this is especially true when determining the onset and quality of a patient's pain. Asking a leading question, such as "Do you have sharp chest pain?" will often lead the patient to say "yes," even though that is not the true quality of his or her pain. Allow the patient to use his or her own words when describing symptoms. A patient's medication regimen includes fluoxetine, Toprol, Proscar, lansoprazole, and Klonopin. Which of these medications is used to treat cardiovascular disorders? Toprol. Toprol (metaprolol) is a commonly prescribed beta-blocker used to treat various cardiovascular conditions, including hypertension and tachydysrhythmias. Proscar (finasteride) is used to treat benign prostatic hyperplasia (BPH). Fluoxetine (Prozac) is a selective serotonin reuptake inhibitor (SSRI) antidepressant. It is used to treat conditions such as depression, generalized anxiety disorder, and obsessive-compulsive disorder (OCD). Lansoprazole (Prevacid)—a proton pump inhibitor—is used to treat conditions such as heartburn, acid reflux disease, and ulcers. Clonazepam (Klonopin) is a benzodiazepine sedative-hypnotic; it is used to treat anxiety. What are the physiologic effects of nitroglycerin when given to patients with cardiac-related chest pain, pressure, or discomfort? Smooth muscle relaxation and decreased preload. Nitroglycerin (NTG) is a vasodilator. It relaxes the smooth muscle of the vascular walls, which promotes systemic venous pooling of blood. As a result, venous return to the right atrium (preload) is decreased; this decreases the cardiac workload. The amount of resistance that the left ventricle must contract against (afterload) is also decreased secondary to vasodilation. By dilating the coronary arteries, NTG increases blood supply to ischemic myocardium and may relieve the chest pain, pressure, or discomfort associated with acute coronary syndrome (ACS). Nitroglycerin is not an analgesic; if it relieves the patient's pain, it is because myocardial oxygen supply and demand have been rebalanced. A transmural myocardial infarction is defined as: An MI that involves the entire thickness of the left ventricular wall from endocardium to epicardium. A transmural myocardial infarction involves the entire thickness of the left ventricular wall from endocardium to epicardium; it is associated with ST- segment elevation and, eventually, the development of pathologic Q waves. A subendocardial infarction involves multiple areas of myocardial necrosis confined to the inner one third to one half of the left ventricular wall; subendocardial infarctions are also referred to as non-Q-wave infarctions. Myocardial ischemia caused by focal areas of spontaneous coronary vasospasm, which may lead to infarction, is called Prinzmetal's (variant) angina; the exact cause of this spontaneous coronary vasospasm is largely unknown. A 60-year-old female presents with confusion, shortness of breath, and diaphoresis. Her blood pressure is 70/40 mm Hg and her heart rate is 40 beats/min. The cardiac monitor reveals a slow, wide complex rhythm with dissociated P waves. After applying supplemental oxygen, you should: Begin immediate transcutaneous pacing. The cardiac rhythm described is a third-degree (complete) AV block, and the patient is clinically unstable (ie, hypotension, altered mental status, shortness of breath). Third-degree AV block is characterized by a slow ventricular rate and no P-to-QRS relationship (AV dissociation). Patients with high-grade AV blocks (eg, second-degree type II, third-degree) are often clinically unstable and require immediate transcutaneous cardiac pacing (TCP). Atropine is an appropriate drug for clinically unstable patients with sinus bradycardia and bradycardia associated with low-grade AV blocks (eg, first-degree, second-degree type I); it is not recommended for high-grade AV blocks. If TCP is unsuccessful for this patient, consider an epinephrine infusion (2 to 10 µg/min) or a dopamine infusion (5 to 10 as these are indicators of myocardial ischemia. ST segment elevation indicates myocardial injury (eg, acute MI in progress). You are assessing the cardiac rhythm of a woman with respiratory distress. The rhythm is irregularly irregular with a rate of 120 beats/min. The QRS complexes measure 0.10 seconds in duration, the P wave to QRS ratio is 1:1, and the P waves vary in shape. This cardiac rhythm is MOST likely: Multifocal atrial tachycardia. In multifocal atrial tachycardia (MAT), the pacemaker of the heart moves within various areas of the atria. MAT is characterized by a ventricular rate that is greater than 100 beats/min. MAT is irregularly irregular, with variation between R-R intervals based on the site of the pacemaker for that particular complex. P waves are present, upright, and precede each QRS complex; however, the shapes of the P waves vary as an indication of their different sites of origin. The P-R interval generally measures between 0.12 and 0.20 seconds, but also varies slightly based on the origin of the particular complex. Atrial fibrillation (A-Fib) is also an irregularly irregular rhythm; however, there are no discernable P waves. A wandering atrial pacemaker essentially contains all the components of MAT; unlike MAT, however, the ventricular rate is typically less than 100 beats/min. Atrial flutter (A-Flutter) has characteristic flutter waves (F waves) that resemble a saw tooth. If accompanied by aberrancy, A-flutter has QRS complexes that are greater than 0.12 seconds in duration, which indicates abnormal (aberrant) ventricular conduction. Which of the following represents the correct medication sequence when treating a patient with a suspected acute coronary syndrome? Oxygen, aspirin, nitroglycerin, and morphine. The mnemonic "MONA" is used to help remember the medications given to patients who are experiencing an acute coronary syndrome (ACS). Although it does not represent the correct sequence in which the medications should be given, it is a useful mnemonic to remember. The appropriate sequence of medications is oxygen (as needed to maintain an SpO2 of greater than 94%), aspirin (160 to 325 mg), nitrogylcerin (0.4 mg up to 3 times), and morphine (2 to 4 mg) if the nitroglycerin does not relieve the chest pain. Pain relief is very important in patients experiencing ACS (eg, unstable angina or AMI) because it reduces anxiety and subsequent oxygen consumption and demand. Which of the following ECG findings indicates a pathologic delay at the AV node? P-R interval of 0.28 seconds. Normally, there is a physiologic delay of an impulse at the AV node that allows the atria to empty into the ventricles. On the ECG, this manifests as a P-R interval—the period of time that includes atrial depolarization and the delay at the AV node—that is between 0.12 and 0.20 seconds (120 to 200 ms). A pathologic delay at the AV node, such as what occurs with a first-degree AV block, would manifest with a P-R interval that is greater than 0.12 seconds (120 ms) in duration. By contrast, A P-R interval that is less than 0.12 seconds indicates that an impulse is traversing the AV node too fast or is bypassing it altogether, such as what occurs with Wolff- Parkinson-White (WPW) syndrome, a preexcitation syndrome in which the electrical impulse follows accessory pathways around the AV node (bundle of Kent) and prematurely depolarizes the ventricles. A wide (> 0.12 seconds [120 ms]) QRS complex indicates an intraventricular conduction delay, such as a bundle branch block. P waves that vary in morphology (appearance) indicate more than one atrial pacemaker site; an example of this is an ectopic atrial rhythm. In contrast to unstable angina, stable angina occurs when a patient: Experiences chest discomfort after a certain, predictable amount of exertion. Angina pectoris is a sign of coronary artery disease (CAD), and is the result of an imbalance in myocardial oxygen supply and demand. Stable angina occurs when the patient experiences chest pain or discomfort after a certain, predictable amount of exertion. Furthermore, the patient with stable angina typically knows what actions to take to relieve the pain (ie, rest, nitroglycerin). By contrast, unstable angina is characterized by noticeable changes in the frequency, severity, and degree of chest pain or discomfort. The patient experiences symptoms, which are often not relieved with rest and/or nitroglycerin, when myocardial oxygen demand is otherwise low (ie, sleep, rest). Unstable angina indicates advanced CAD; it is commonly referred to as preinfarction angina. According to the Los Angeles Prehospital Stroke Screen (LAPSS), the likelihood that a conscious patient with an acute atraumatic neurologic complaint is experiencing a stroke is HIGHEST if he or she: Does not have a history of seizures. The Los Angeles Prehospital Stroke Screen (LAPSS) is a useful tool for indentifying patients who are possibly experiencing a stroke. It requires the paramedic to rule out other causes of abnormal neurologic signs (eg, seizures, hypoglycemia). There are six components to the LAPSS. If any one of these items is checked "yes" or "unknown," you should notify the receiving facility as soon as possible and inform them that the patient is potentially experiencing a stroke. Bear in mind, however, that some patients who are experiencing a stroke may have unremarkable findings on the LAPSS (eg, all components of the LAPSS are checked "no"). Following are the six components of the LAPSS: (1) Age > 45 years; (2) History of seizures is absent; (3) Patient is not normally bedridden or confined to a wheelchair; (4) Blood glucose level is between 60 and 400 mg/dL; (5) Symptom duration is < 24 hours; (6) Unilateral asymmetry in any of the following categories: Facial smile/grimace, Grip strength, or Arm strength (eg, arm drift). Which of the following statements regarding right ventricular failure (RVF) is correct? Sacral and pedal edema are common signs of RVF. The most common cause of right ventricular failure (RVF) is left ventricular failure (LVF). When the left ventricle fails, blood backs up into the lungs is acute, is of maximal intensity from the onset, and is usually described as a ripping, tearing, or stabbing feeling. Other signs and symptoms depend on the extent and location of the dissection. In dissections of the ascending aorta, one or more of the vessels of the aortic arch may be compromised. Disruption of blood flow through the innominate artery, for example, is likely to produce a difference in blood pressure between the arms. The onset and pain characteristics of abdominal aortic dissection are similar to those of ascending aortic dissection; however, the pain typically begins in the abdomen or lower back. Pulse deficits in the femoral arteries may be present, and if the aneurysm is leaking blood into the retroperitoneal space, the patient may complain of an urge to defecate and exhibit signs of shock. A 56-year-old man has had chest pain for the past 2 days, but refused to go to the hospital. His wife called EMS when she noticed that he was not acting right. He is conscious, but confused, and is diaphoretic. His BP is 80/40 mm Hg and his pulse is rapid and weak. The patient's history and your assessment findings are MOST consistent with: Cardiogenic hypoperfusion. The patient most likely experienced an acute myocardial infarction (AMI); however, since he did not receive timely treatment, extensive myocardial damage has resulted in pump failure. His low BP; weak, rapid pulses; and altered mental status indicate that he is systemically hypoperfused. Hypoperfusion (shock) secondary to a cardiac etiology (ie, pump failure, fast or slow heart rate) is called cardiogenic shock. True cardiogenic shock, which occurs when the myocardium is extensively and permanently damaged and can no longer meet the metabolic needs of the body, has a high mortality rate. What is the therapeutic effect of aspirin when administered to a patient experiencing an acute coronary syndrome (ACS)? Decreased thromboxane A2 production, which inhibits platelet aggregation. Thromboxane A2 is produced by activated platelets. It is a potent vasoconstrictor, it stimulates activation of new platelets, and it increases platelet aggregation. Aspirin (acetylsalicylic acid [ASA]) blocks the production of thromboxane A2, which inhibits vasoconstriction, inhibits activation of new platelets, and inhibits platelet aggregation (ie, it makes the platelets less "sticky"). Aspirin does not destroy a clot in a coronary artery—it prevents it from getting larger. Furthermore, by inhibiting local coronary vasoconstriction, it may enhance blood flow around the clot. Fibrinolytic agents (ie, alteplase [Activase], streptokinase [Streptase], tenecteplase [TNKase]) convert the body's own clot-dissolving enzyme from its inactive form, plasminogen, to its active form, plasmin. Plasmin then destroys the fibrin matrix of the clot—hence the term "fibrinolysis." We have an expert-written solution to this problem! You are assessing a 67-year-old female with chest discomfort when she becomes unresponsive, apneic, and pulseless. The cardiac monitor reveals coarse ventricular fibrillation. You achieve return of spontaneous circulation after 6 minutes and the cardiac monitor now reveals a narrow complex rhythm. The patient is still unresponsive, has occasional respirations, a blood pressure of 70/40 mm Hg, and a weak pulse of 70 beats/min. The MOST appropriate postresuscitation care for this patient includes: Insertion of an airway adjunct, assisted ventilation, vascular access, a 500-mL crystalloid bolus, an antidysrhythmic, and consideration for induced hypothermia. If return of spontaneous circulation (ROSC) occurs, you must focus on preventing recurrent cardiac arrest and providing optimal conditions that enhance neurologic recovery. Immediately following ROSC, reassess the patient's airway and breathing and treat accordingly. For this patient, you should insert an airway adjunct and assist her ventilations with a bag- mask device and high-flow oxygen. If her breathing does not improve, and she remains unresponsive, an advanced airway device should be considered. Her heart rate (70 beats/min) does not require treatment, although you must closely monitor it. Her blood pressure, however, is low and should be treated. Marked hypotension must be corrected in order to minimize cerebral ischemia; this is usually accomplished initially with crystalloid fluid boluses. If fluid boluses are unsuccessful, an inotropic drug (eg, dopamine) should be considered. Because the patient is still unresponsive, you should consider inducing therapeutic hypothermia, depending on your local protocols. The induction of hypothermia following ROSC has been shown to improve neurologic recovery. The postresuscitation cardiac rhythm should be stabilized to the extent possible. If the arrest rhythm was V-Fib or pulseless V-Tach, consider an antidysrhythmic bolus (eg, lidocaine, amiodarone), followed by an infusion of that same drug. You are attempting to resuscitate a 50-year-old man in cardiac arrest. The patient has a history of congestive heart failure, hypertension, and cirrhosis of the liver. The cardiac monitor reveals a slow, wide complex rhythm. CPR is ongoing and the patient has been intubated. In addition to looking for potentially reversible causes of the patient's condition, further treatment should include: Ventilations at a rate of 8 to 10 breaths/min and 1 mg of epinephrine 1:10,000 every 3 to 5 minutes. Pulseless electrical activity (PEA) refers to the presence of an organized cardiac rhythm (except V-Tach), despite the absence of a pulse; it can result from a variety of conditions, such as hypovolemia, overdose, hypothermia, and trauma, among others. Treatment for PEA includes high- quality CPR with minimal interruptions, 1 mg of epinephrine 1:10,000 every 3 to 5 minutes, advanced airway management, and treating potentially reversible causes. A one-time 40-unit dose of vasopressin can be given to replace the first or second dose of epinephrine, but not both. After an advanced airway device is in place, perform asynchronous CPR; the compressor delivers at least 100 compressions/min and the ventilator provides 8 to 10 breaths/min (one breath every 6 to 8 seconds). Do not hyperventilate the patient; doing so may impair venous return to the heart and decrease cardiac output. A ventilation rate of 12 to 20 breaths/min is appropriate for infants and children who are apneic, but have a pulse. An apneic adult with a pulse should be ventilated at a rate of 10 to 12 breaths/min. Dopamine is not indicated for patients in cardiac arrest, and current evidence does not support the use of transcutaneous cardiac pacing (TCP) in patients with PEA or asystole. the ventricle during the beginning of diastole. An S3 sound should occur 120 to 170 milliseconds after S2, if it is heard at all. An S3 sound may be a normal clinical finding in children and young adults, although a cardiac evaluation should be performed to determine this. When it is heard in older adults, however, it signifies moderate to severe heart failure. S1 is heard near the beginning of ventricular contraction (systole), when the tricuspid and mitral valves close. S2 is heard near the beginning of ventricular relaxation (diastole), when the pulmonic and aortic valves close. You are called to a local supermarket where a customer collapsed. When you arrive, two bystanders are performing CPR on the patient. You should: Assess the patient to confirm pulselessness and apnea. When you arrive at a scene and find bystanders performing CPR, you should briefly pause and confirm that the patient is pulseless and apneic. In some cases, you will find CPR being performed on patients who do not require it. Once cardiac arrest is confirmed, resume high-quality CPR and assess the patient's cardiac rhythm as soon as possible. According to the 2010 guidelines for CPR and emergency cardiac care (ECC), the precordial thump should not be used for unwitnessed out-of-hospital cardiac arrest. However, it may be considered for patients with witnessed, monitored unstable ventricular tachycardia, including pulseless ventricular tachycardia, if a defibrillator is not immediately ready for use. Which of the following causes of pulseless electrical activity (PEA) would be the MOST likely to respond to immediate treatment in the prehospital setting? Hypovolemia. Hypovolemia is the most easily correctable cause of PEA, provided that immediate treatment is given in the prehospital setting. In addition to CPR, airway management, and epinephrine, fluid boluses are repeatedly given, followed by a reassessment of the patient's condition. Remember, myocardial contraction is dependent on electricity and pressure. This pressure is caused as blood fills the heart. If there is no blood, the heart will not pump, even though electrical activity continues. Drug overdose is the underlying cause of asystole that would most likely respond to immediate prehospital treatment, especially in younger patients. Hypokalemia is treated with potassium chloride, which is not administered in the prehospital setting. Lactic acidosis is treated with effective ventilation first, and then sodium bicarbonate if local protocol permits. While sodium bicarbonate can be given in the prehospital setting, paramedics do not have the ability to quantify the pH or bicarbonate level of the patient's blood; this requires arterial blood gas analysis. A 60-year-old man presents with chest discomfort, diaphoresis, and dyspnea. The 12-lead ECG reveals 4-mm ST segment elevation in leads V1 through V4. You should suspect: Anteroseptal injury. The precordial (chest) leads view the following aspects of the heart: V1 and V2, interventricular septum; V3 and V4, anterior wall; V5 and V6, lateral wall. ST segment depression and/or T wave inversion in two or more contiguous leads indicates ischemia. ST segment that is equal to or greater than 1-mm in two or more contiguous leads indicates injury. A developing Q wave may be seen in conjunction with ST segment elevation associated with myocardial injury. Therefore, 4-mm ST segment elevation in leads V1 through V4 indicates an anteroseptal injury pattern (acute MI in progress). Infarcted (dead [necrotic]) myocardium is characterized by poor R wave progression in the precordial leads and/or the presence of a pathologic Q wave in two or more contiguous leads. By definition, a pathologic Q wave is wider than 0.04 seconds (40 ms) or deeper than one third the height of the R wave that follows it. You and your team are performing CPR on a middle-aged male who presented with asystole. After 2 minutes of CPR, you reassess him and note that his cardiac rhythm has changed to ventricular fibrillation. You should: Defibrillate and then resume CPR. CPR alone rarely, if ever, converts asystole—or any other cardiac arrest rhythm—to a perfusing rhythm. Furthermore, if one of the leads detaches from the patient's chest, you will more likely see something that resembles massive artifact, not ventricular fibrillation (V-Fib). If you see V- Fib on the cardiac monitor, defibrillate one time with 360 monophasic joules (or equivalent biphasic) and then immediately resume CPR, starting with chest compressions. Assessing for a carotid pulse in a patient who is clearly in V-Fib wastes time; it delays defibrillation and CPR. After 2 minutes of CPR, reassess the patient's cardiac rhythm; if V-fib is still present, defibrillate one time and immediately resume CPR. If you see an organized cardiac rhythm, assess for a pulse for at least 5 seconds but no more than 10 seconds, and then resume CPR if indicated. You are assessing a man with a acute chest pain. As you are inquiring about the quality of his pain, he clenches his fist. This is called __________ sign and nonverbally conveys a feeling of: Levine's, pressure. Patients with an acute coronary syndrome (ACS)—that is, unstable angina or acute myocardial infarction—often clench their fist when describing the quality of their chest pain or discomfort. This is called Levine's sign, and it conveys a feeling of pressure in the chest. The pain associated with ACS may also be described as a dull or aching sensation or as a feeling of heaviness. An ACS patient who complains of fluttering in the chest should make you suspicious for a cardiac dysrhythmia (ie, SVT, V-Tach). Cullen's sign is characterized by periumbilical bruising and indicates blood in the peritoneal space. Grey-Turner's sign—bruising to the flank area—also indicates blood in the peritoneal space. Beck's triad is a trio of clinical findings that indicates a cardiac tamponade; it includes jugular venous distention, muffled or distant heart sounds, and a narrowing pulse pressure. In which of the following situations is transcutaneous cardiac pacing (TCP) clearly indicated? Third-degree AV block in a patient with pulmonary edema. appropriate intervention if the patient was clinically stable. Adenosine is used for clinically stable patients with narrow-complex tachycardias and can be considered for clinically stable patients with wide-complex monomorphic tachycardias. During your SAMPLE history of an elderly man, he tells you that his cardiologist told him that he has an "irregular heartbeat." His medications include warfarin sodium and digoxin. On the basis of this information, what underlying cardiac rhythm should you suspect? Atrial fibrillation. Patients with atrial fibrillation (A-Fib) are commonly prescribed digoxin (a digitalis preparation) and warfarin sodium (Coumadin), which is a blood thinner. As the atria fibrillate, blood has a tendency to stagnate and form microemboli that can be ejected from the heart and occlude a pulmonary, cerebral, or coronary artery. We have an expert-written solution to this problem! You are assessing a middle-aged female who complains of chest discomfort. She is conscious, alert, and oriented. Her skin is diaphoretic. Her blood pressure is 122/72 mm Hg, her pulse rate is 120 beats/min, and her respirations are 20 breaths/min. On the basis of her chief complaint, which of your assessment findings is the MOST significant? Pulse rate of 120 beats/min. Your patient has signs and symptoms of an acute coronary syndrome (ACS)—a spectrum of cardiac diseases that includes unstable angina pectoris and acute myocardial infarction. In ACS, tachycardia increases myocardial oxygen consumption and demand, and may exacerbate myocardial ischemia or injury. Therefore, her heart rate of 120 beats/min is the most significant clinical finding. Stimulation of the sympathetic nervous system increases the production of sweat, resulting in diaphoresis. Although this is a clinically significant finding, it is not detrimental to the patient. The patient's mental status—conscious, alert, and oriented—indicates that her brain is adequately perfused; obviously, this is a positive sign. Her respiratory rate of 20 breaths/min is consistent with the upper limit of normal for an adult. Ventricular ejection fraction is defined as the: Percentage of blood in the ventricle pumped out during a contraction. Ejection fraction (EF) is the percentage of blood that is pumped from the ventricle per contraction. The total volume of blood pumped out of the ventricle per contraction is called the stroke volume (SV). If the ventricle contains 100 mL of blood before a contraction, but only ejects 55 mL when it contracts (SV), the ejection fraction is 55% (100 mL × 0.55 = 55 mL). Ejection fraction should be at least 65% in the adult. Cardiac output (CO) is the volume of blood ejected from the left ventricle each minute, and is calculated by multiplying the stroke volume by the heart rate; in the adult, this is typically 5 to 6 L/min. You are evaluating a regular cardiac rhythm in lead II. The rate is 90 beats/min, the QRS complexes consistently measure 0.16 seconds, and inverted P waves are seen immediately following each QRS complex. The rhythm described is MOST characteristic of a/an: Accelerated junctional rhythm with ventricular aberrancy. A junctional rhythm is characterized by inverted P waves in lead II. If seen, the inverted P waves precede or follow the QRS complex. At a rate of 90 beats/min, the rhythm is further defined as an accelerated junctional rhythm. QRS complexes greater than 0.12 seconds (120 ms) indicate aberrant (abnormal) ventricular conduction (ie, bundle branch block). A wandering atrial pacemaker is characterized by P waves that precede each QRS complex, but vary in morphology. An ectopic atrial rhythm is also characterized by P waves of varying morphologies as well as varying PR intervals. A second- or third-degree AV block should be suspected when there are more P waves than QRS complexes. You are assessing a 59-year-old woman who complains of chest pressure. When you are looking at her list of medications, you note that she takes Vasotec. What type of medication is this? ACE inhibitor. Enalapril maleate (Vasotec) is an ACE (angiotensin converting enzyme) inhibitor that is used to treat hypertension. Angiotensin II, a potent chemical produced by the kidneys that causes vasoconstriction, is formed from angiotensin I in the blood by the angiotensin converting enzyme. ACE inhibitors inhibit the activity of this enzyme, which decreases the production of angiotensin II. As a result, the blood vessels dilate and blood pressure is reduced. Beta blockers, which are also used to treat hypertension, include drugs such as metoprolol (Lopressor), propranolol (Inderal), and atenolol (Tenormin), among others. Calcium channel blockers are also used to treat hypertension, and include drugs such as diltiazem (Cardizem), verapamil (Calan; Isoptin), and amlodipine (Norvasc), among others. Atropine sulfate is a parasympathetic blocker (vagolytic) that is used to treat patients with hemodynamically unstable bradycardia. We have an expert-written solution to this problem! An elderly man is apneic and pulseless. The ECG shows the following rhythm, which you should interpret as: Sinus tachycardia. The rhythm shown is sinus tachycardia at a rate of approximately 100 to 110 beats/min. First-degree AV block is characterized by a PR interval that is greater than 0.20 seconds, the normal being 0.12 to 0.20 seconds (120 to 200 milliseconds). The fact that the patient does not have a pulse indicates pulseless electrical activity (PEA). PEA is not a specific rhythm; it is a condition in which a pulseless, apneic patient presents with an organized cardiac rhythm (except for pulseless V-Tach). Where is the point of maximal impulse (PMI) located in most people? After determining that an elderly man is pulseless and apneic, you and your team begin CPR and briefly pause to assess his cardiac rhythm, which is shown below. After resuming CPR, you should: Establish vascular access and give 1 mg of epinephrine. After determining that a patient is in pulseless electrical activity (PEA), you should resume CPR, establish vascular access (IV or IO), and administer 1 mg of epinephrine 1:10,000. Consider inserting an advanced airway (ie, ET tube, multilumen airway, supraglottic airway), but DO NOT interrupt CPR to do this. Focus on ruling out potentially reversible causes (Hs and Ts). Routine administration of sodium bicarbonate during cardiac arrest is not recommended; its administration should be guided by arterial blood gas (ABG) values. Synchronized cardioversion is indicated for hemodynamically unstable patients with wide and narrow complex tachycardias, not PEA. When treating an adult patient with a blood pressure of 60/40 mm Hg, confusion, a heart rate of 40 beats/min, and sinus bradycardia on the cardiac monitor, you should administer supplemental oxygen, establish vascular access, and then: Administer 0.5 mg of atropine sulfate and consider transcutaneous cardiac pacing. A patient who presents with or develops symptomatic bradycardia needs to be treated in a manner that will increase the heart rate, thus improving cardiac output, blood pressure, and mental status. Altered mental status, hypotension, chest pain or pressure, and shortness of breath are indications for treatment of the bradycardic patient. After ensuring adequate oxygenation and ventilation, establish vascular access and give 0.5 mg of atropine; this may be repeated every 3 to 5 minutes to a maximum dose of 3 mg. If the patient is severely compromised or does not respond to atropine, begin transcutaneous cardiac pacing (TCP) without delay. If the patient is in a second-degree type II or third-degree AV block, TCP is the first-line treatment. Atropine and TCP-refractory bradycardia may require a sympathomimetic infusion, such as epinephrine or dopamine. The body's normal physiologic response to hypovolemia is tachycardia, not bradycardia. Therefore, fluid boluses are not the initial treatment for the hypotensive, bradycardic patient. In fact, they may cause further harm to the patient. With a slow heart rate and decreased cardiac output, a sudden increase in preload may result in acute pulmonary edema. After stabilizing the patient's heart rate and improving perfusion, obtain a 12-lead ECG to assess for signs of acute myocardial ischemia or injury. You are transporting a 62-year-old male who called EMS because of nausea and diarrhea. His past medical history includes high cholesterol, for which he takes Lipitor; he denies any other medical history. His blood pressure is 132/78 mm Hg, pulse is 68 beats/min, and respirations are 16 breaths/min. He is receiving oxygen via nasal cannula and has a patent IV line established. He has been in a normal sinus rhythm, but is now experiencing occasional premature ventricular complexes (PVCs). After noting the PVCs, you should: Reassess and continue monitoring him. The patient in this scenario is hemodynamically stable. Premature ventricular complexes (PVCs) are generally not a cause for concern unless they are frequent (> 6 per minute) or occur in the context of acute coronary syndrome (ACS) or hemodynamic compromise. Nonetheless, any change in the patient's condition warrants reassessment. Continue monitoring the ECG and his vital signs. If the PVCs become more frequent, or if his condition deteriorates, an antidysrhythmic (eg, lidocaine, amiodarone) may be indicated. The patient's current vital signs are not suggestive of hypovolemia; therefore, a fluid bolus is not indicated at this point. Call your radio report to the receiving facility as usual and report your findings at that time; there is no need to contact them "immediately." Which of the following findings is MOST suggestive of right-sided heart failure? Engorged jugular veins. As the right side of the heart fails, blood is not effectively ejected into the pulmonary circulation; therefore, it backs up beyond the right atrium and into the systemic venous system. This is most noticeable by the presence of engorged or distended jugular veins. Orthopnea, nocturnal dyspnea, and coughing up blood-tinged sputum are indicators of left-sided heart failure as they all indicate fluid in the lungs. What occurs at the beginning of ventricular contraction? The atrioventricular valves close and the semilunar valves are forced open. As ventricular contraction begins, the atrioventricular valves (tricuspid and mitral) close and the semilunar valves (pulmonic and aortic) are forced open. As a result, blood moves from the right ventricle through the pulmonary arteries and from the left ventricle through the aorta and into the systemic circulation. The majority of ventricular filling occurs by gravity. Atrial kick is the volume of blood that the atria contribute to ventricular filling; this occurs before ventricular contraction. Increased pressure within the myocardium (ie, increased blood volume) causes stretching of the myocardial walls, thus increasing the force of its contraction (Starling effect); this process precedes ventricular contraction. A middle-aged man is found unresponsive, pulseless, and apneic. His cardiac arrest was not witnessed, although his skin is still warm to the touch. You should: Begin immediate high-quality CPR. The first and most crucial intervention for any patient in cardiac arrest is immediate high-quality CPR. With CPR ongoing, you or your partner can apply the defibrillation pads and assess the patient's cardiac rhythm. If a shock is indicated, deliver it and immediately resume CPR, starting with chest compressions. During the 2-minute cycles of CPR, vascular access can be obtained, cardiac drugs can be administered, and the patient's airway can be secured with an advanced device if necessary. It is absolutely critical to minimize interruptions in chest compressions; if you must interrupt compressions, do so for no longer than 10 seconds. The precordial thump is not indicated for unwitnessed cardiac arrest; it may be considered for patients with witnessed V-Tach, however, but has a low success rate. rhythm. However, if signs of hemodynamic instability are noted (ie, hypotension, decreased level of consciousness, chest pain, shortness of breath), perform synchronized cardioversion at 50 to 100 joules without delay. You are assessing a 75-year-old male who experienced a sudden onset of slurred speech, a right-sided facial droop, and left-sided hemiparesis approximately 45 minutes ago. His blood pressure is 170/94 mm Hg, pulse rate is 68 beats/min and irregular, and respirations are 14 breaths/min and unlabored. His oxygen saturation is 94% on room air. The MOST appropriate treatment for this patient includes: Supplemental oxygen via nasal cannula, cardiac monitoring, blood glucose assessment, an IV of normal saline set to keep the vein open, and prompt transport. The patient is likely experiencing an acute ischemic stroke. Determining the time of onset of his symptoms is critical; fibrinolytic therapy must be administered within the first 3 hours following a stroke in order to be of maximum benefit. Treatment includes supplemental oxygen (a nasal cannula is appropriate, given his room air oxygen saturation), blood glucose assessment (hypoglycemia can mimic certain signs of a stroke), vascular access, cardiac monitoring, and prompt transport with early notification of the receiving facility. Do not give aspirin to suspected stroke patients in the field; it can cause further harm to the patient with a hemorrhagic stroke. Aspirin may be given at the hospital after a hemorrhagic stroke is ruled out with a computed tomography (CT) scan of the brain. Antihypertensive therapy should also be avoided in the field; it should be performed in the controlled setting of a hospital, where the patient has invasive hemodynamic monitoring. Lowering a patient's BP in the field is dangerous and can have disastrous effects; inadvertently inducing hypotension in the stroke patient may exacerbate cerebral ischemia. Side effects of atropine sulfate may include: Acute urinary retention. Side effects of atropine sulfate may include thirst, dry mouth, pupillary dilation (mydriasis), tachycardia, hypertension, and urinary retention. Acute urinary retention is especially common in older men with benign prostatic hyperplasia (BPH), also known as an enlarged prostate gland. While assessing a middle-aged man who complains of nausea and weakness, he suddenly becomes unresponsive. The cardiac monitor displays the rhythm shown below. After determining that he is apneic and pulseless, you should: Start CPR and prepare to defibrillate. You witnessed your patient's deterioration to cardiac arrest, and he is now in ventricular fibrillation (V-Fib). You should immediately start CPR and defibrillate as soon as possible. Deliver a single shock with 360 monophasic joules or the equivalent biphasic setting, and immediately resume CPR (starting with chest compressions). Perform 5 cycles (about 2 minutes) of CPR and then reassess his cardiac rhythm. If V-Fib persists, defibrillate again and immediately resume CPR, starting with chest compressions. During CPR, establish vascular access (if not already done), and give 1 mg of epinephrine 1:10,000. After 2 minutes of CPR, reassess the patient's cardiac rhythm. If V-Fib persists, defibrillate again and immediately resume CPR, starting with chest compressions. It would then be appropriate to administer 300 mg of amiodarone. Synchronized cardioversion is indicated for patients with narrow or wide-complex tachycardias who are hemodynamically unstable but have a pulse. A 70-year-old man presents with the cardiac rhythm shown below. He is confused, is slow to answer your questions, and is profusely diaphoretic. His blood pressure is 76/54 mm Hg, his pulse is rapid and weak, and his respirations are 22 breaths/min and labored. He is receiving high-flow oxygen and your partner has established a patent IV line. You should: Consider sedation and then cardiovert with 100 joules. This patient is in ventricular tachycardia (V-Tach). Furthermore, he is hemodynamically unstable as evidenced by his confusion, hypotension, and labored breathing. Therefore, he requires prompt synchronized cardioversion, starting with 100 joules. Consider sedation with midazolam (Versed) or diazepam (Valium), but do not allow this to delay cardioversion. Amiodarone would be an appropriate intervention if the patient was hemodynamically stable. Vagal maneuvers and adenosine are appropriate for stable patients with narrow complex tachycardias (eg, SVT). Fluid boluses will likely not improve the patient's blood pressure; his hypotension is the result of inadequate ventricular filling and decreased cardiac output due to his cardiac rhythm—not hypovolemia. You are transporting a 60-year-old woman with chest discomfort and diaphoresis. The 12-lead ECG indicates an acute anterior wall MI. The patient is receiving oxygen and an IV has been established. You have administered 324 mg of aspirin, 3 sublingual nitroglycerin, and 5 mg of morphine. Which of the following should concern you the MOST during transport? An acute cardiac dysrhythmia. More than 500,000 deaths occur each year as the result of acute myocardial infarction (AMI). Sixty to seventy percent of these deaths occur outside the hospital, usually during the first few hours after the onset of symptoms. Of all deaths from AMI, 90% are due to dysrhythmias—usually ventricular fibrillation—which typically occur during the early hours of the infarct; this should be your primary concern. Many patients experiencing an anterior wall MI are hyperdynamic—that is, they are hypertensive and tachycardic; hypotension is not as common. Depression of the CNS (respiratory depression, bradycardia, and hypotension) should be a concern any time you administer a narcotic analgesic (ie, morphine); however, most patients do not experience significant CNS depression with 5 mg of morphine. Pain relief is an important aspect in the management of the patient with AMI; minimizing pain minimizes anxiety, which can limit the size of the infarct. A 50-year-old woman is pulseless and apneic. Your partner and an emergency medical responder are performing well-coordinated CPR. After 2 minutes of CPR, the cardiac monitor reveals coarse ventricular fibrillation. You should: Which of the following 12-lead ECG findings signifies a left bundle branch block? QRS duration of 124 ms; terminal S wave in lead V1 . A QRS duration of greater than 120 ms (0.12 seconds [3 small boxes]) signifies an intraventricular conduction delay (IVCD), such as a bundle branch block. A left bundle branch block (LBBB) is characterized by a QRS duration of greater than 120 ms and a terminal S wave in lead V1 (the second half of the QRS complex terminates in an S wave); terminal R waves are seen in leads I, aVL, and V6. A right bundle branch block (RBBB) is characterized by a QRS duration of greater than 120 ms and a terminal R wave in lead V1 (the second half of the QRS complex terminates in an R wave); terminal S waves are seen in leads I, aVL, and V6. Unlike a second-degree AV block type I, a second-degree AV block type II is characterized by: Consistent P-R intervals following conducted P waves. A second-degree AV block Mobitz Type II (classic second-degree AV block) is characterized by more P waves than QRS complexes. However, the P-R intervals of the conducted complexes (P waves that are followed by a QRS complex)—whether shortened, normal, or prolonged—are consistent. By contrast, a second-degree AV block Mobitz Type I (Wenkebach) is characterized by a progressive lengthening of the P-R interval until a P wave is blocked (not followed by a QRS complex). The ventricular rate of a second-degree AV block may be normal or slow. Dissociation of the P waves and QRS complexes is characteristic of a third-degree (complete) AV block. We have an expert-written solution to this problem! When administering a sympathomimetic medication, you must be alert for: Cardiac arrhythmias. Sympathomimetic medications, such as epinephrine and norepinephrine, cause increases in myocardial oxygen demand and consumption. If given to patients with hypoxemia or acute coronary syndrome (eg, unstable angina, acute myocardial infarction), this effect can result in cardiac arrhythmias. Therefore, you should monitor the cardiac rhythm of any patient who receives a sympathomimetic drug. Sympathomimetic drugs cause an increase in heart rate, not a decrease. Hypotension and respiratory failure are not common following the administration of a sympathomimetic drug. The appropriate second dose and method of administration of amiodarone for a patient with refractory ventricular fibrillation is: 150 mg via rapid IV/IO push. The initial dose of amiodarone for a patient with refractory ventricular fibrillation or pulseless ventricular tachycardia is 300 mg via rapid IV or IO push. A second dose of 150 mg via rapid IV or IO push may be repeated one time in 5 minutes. For supraventricular tachycardia or ventricular tachycardia with a pulse, amiodarone should be given in a dose of 150 mg over 10 minutes; this same dose may be repeated as needed. You should interpret the following cardiac rhythm as: Type I second-degree AV block. The progressive lengthening of the PR interval until a P wave is blocked (not followed by a QRS complex) makes this cardiac rhythm a type I second-degree AV block, also referred to as "Wenckebach." This type of AV heart block represents a progressive delay at the AV node/junction until an electrical impulse is completely blocked from entering the ventricles. A type II second-degree AV block is characterized by more P waves than QRS complexes; however, the P-R intervals of the conducted complexes are consistent. In complete AV dissociation (ie, third-degree AV block), there are more P waves than QRS complexes, and no relationship exists between a given P wave and QRS complex. A wandering atrial pacemaker is characterized by varying morphologies of P waves. Which of the following pain descriptions is MOST consistent with a cardiac problem? Crushing. Chest pain of cardiac origin is most often described as crushing, dull, pressure, or as a feeling of heaviness or discomfort. The pain is typically constant, not intermittent, and is usually not palliated or exacerbated by movement. Bear in mind that these are typical pain descriptions. The paramedic should not rule out a cardiac problem if the patient describes the pain differently. Sharp (pleuritic) pain is often associated with conditions such as pleurisy, pulmonary embolism, or spontaneous pneumothorax. A tearing sensation should alert you to the possibility of acute aortic dissection. Where is the point of maximal impulse (PMI) located in most people? A: Directly over the sternum, approximately 1" to the left of the angle of Louis B: Left anterior chest, in the midclavicular line, at the fifth intercostal space C: Left anterior chest, on the left sternal border, at the fourth intercostal space D: Left anterolateral chest, in the midaxillary line, at the fifth intercostal space B: Left anterior chest, in the midclavicular line, at the fifth intercostal space When administering epinephrine to a patient in cardiac arrest, the MAIN desired effect is: intracranial lesion (eg, brain tumor) typically have a slow onset and insidious progression of symptoms—often over a period of months. In some patients with a brain tumor, a seizure may be the only presenting clinical manifestation. A 49-year-old male complains of generalized weakness that began about a week ago. He is conscious and alert and is breathing adequately. His blood pressure is 138/78 mm Hg, pulse is 130 beats/min and irregular, and respirations are 14 breaths/min. You administer supplemental oxygen and apply the cardiac monitor, which reveals atrial fibrillation; a 12-lead ECG tracing reveals the same. The patient denies any significant medical problems and takes no medications. After establishing IV access, you should: A: sedate with midazolam and perform synchronized cardioversion. B: attempt vagal maneuvers and then give 6 mg of adenosine IV push. C: give 150 mg of amiodarone over 10 minutes and transport. D: administer 0.25 mg/kg of diltiazem and transport for evaluation. D: administer 0.25 mg/kg of diltiazem and transport for evaluation. Reason: In the absence of any significant medical history, this patient's weakness probably signaled the onset of his atrial fibrillation (A-Fib). New-onset A-Fib of greater than 48 hours' duration should not be treated with synchronized cardioversion until the patient is adequately anticoagulated first (ie, Coumadin). Blood can stagnate in the fibrillating atria, which increases the risk of clot formation; cardioversion may dislodge these clots, resulting in a stroke, pulmonary embolism, or myocardial infarction. Furthermore, this patient is hemodynamically stable and is not in need of electrical therapy. Appropriate treatment for a patient with A-Fib or atrial flutter (A-Flutter) with a rapid ventricular rate (RVR) involves controlling the ventricular rate with a calcium-channel blocker. Diltiazem (Cardizem) is the most common drug used for this purpose. The initial dose is 0.25 mg/kg, which may be repeated in 15 minutes in a dose of 0.35 mg/kg. Amiodarone may be used to terminate new-onset A-Fib or A-Flutter, but is uncommonly given for this purpose in the prehospital setting. Vagal maneuvers and adenosine are indicated for narrow-complex tachycardias in an attempt to slow the ventricular rate so you can identify the underlying rhythm. You have already identified this patient's rhythm. Which of the following interventions has the greatest impact on patient survival from sudden cardiac arrest? A: Identifying the cause B: Cardiac medication administration C: Early CPR and defibrillation D: Advanced airway control C: Early CPR and defibrillation Reason: Early CPR and defibrillation are the two interventions that will have the greatest impact on patient survival from sudden cardiac arrest (SCA). Early, effective CPR maintains perfusion to the body's vital organs until defibrillation can be provided. The most common initial cardiac rhythm observed during SCA is ventricular fibrillation (V-Fib). Early defibrillation, in conjunction with early CPR, greatly enhances the chance of establishing return of spontaneous circulation (ROSC). The probability of successful defibrillation decreases over time, especially if CPR is delayed. For each minute that V-Fib persists, the patient's chance of survival decreases by approximately 7% to 10%. During resuscitation of a 60-year-old man with ventricular fibrillation, you restore spontaneous circulation following CPR, defibrillation, two doses of epinephrine, and one dose of amiodarone. The patient remains unresponsive and apneic. Which of the following represents the MOST appropriate post-arrest care for this patient? A: Ventilate at a rate of 20 breaths/min, begin an epinephrine infusion to maintain perfusion, and keep the patient warm B: Ventilate at a rate of 8 to 10 breaths/min, support blood pressure, and give 150 mg of amiodarone over 10 minutes C: Ventilate at a rate of 10 to 12 breaths/min, support blood pressure, and consider therapeutic hypothermia D: Hyperventilate the patient, administer a normal saline bolus, and begin an amiodarone infusion at 0.5 mg/min C: Ventilate at a rate of 10 to 12 breaths/min, support blood pressure, and consider therapeutic hypothermia Reason: The 2010 guidelines for CPR and emergency cardiac care (ECC) have added a fifth link to the chain of survival, integrated post-arrest care. In addition to supporting the patient's airway and ventilatory status and supporting his or her blood pressure with IV fluid boluses or an inotropic agent (ie, dopamine), you should assess for and correct any glucose abnormalities. If the patient is unable to follow verbal commands or remains comatose following return of spontaneous circulation (ROSC), therapeutic hypothermia (89.6°F to 93.2°F [32°C to 34°C]) has been shown to improve neurologic recovery and should be considered (follow your local protocols regarding therapeutic hypothermia). Once ROSC has been established, you should continue to ventilate the adult patient at a rate of 10 to 12 breaths/min (one breath every 5 to 6 seconds) if he or she remains apneic. DO NOT hyperventilate the patient as this may impair venous return to the heart and compromise cardiac output. If the patient is able to follow verbal commands following ROSC, obtain a 12-lead ECG tracing and assess for signs of acute MI (ie, ST elevation). Depending on your transport time, you may consider starting a maintenance infusion of the antidysrhythmic drug that was administered during the arrest, which in this case, would be amiodarone (1 mg/min). You are preparing to defibrillate a patient in cardiac arrest with a manual biphasic defibrillator, but are unsure of the appropriate initial energy setting. What should you do? A: Continue CPR and shock with 360 joules in 2 minutes. B: Contact medical control for further guidance. C: Deliver one shock with 200 joules and resume CPR. D: Deliver three sequential shocks with 120 joules. C: Deliver one shock with 200 joules and resume CPR. Reason: Energy settings for manual biphasic defibrillators are device-specific— typically 120 joules (rectilinear) or 150 joules (truncated). However, if the appropriate initial energy setting is unknown, you should defibrillate with 200 joules. For subsequent shocks, use the same or higher energy setting. of little or no benefit to patients with PEA or asystole, and it is clearly of no benefit to patients with prolonged asystole. You are treating a 68-year-old woman with chest pressure and shortness of breath that started 2 days ago. Her BP is 76/52 mm Hg and her pulse is 130 beats/min and weak. The cardiac monitor reveals sinus tachycardia with occasional PVCs and auscultation of her lungs reveals diffuse coarse crackles. Which of the following treatment interventions is MOST appropriate for this patient? A: Dopamine, 2 to 20 µg/kg/min. B: Nitroglycerin, 10 to 20 µg/min. C: Amiodarone, 150 mg over 10 min. D: Normal saline, 20 mL/kg rapid bolus. A: Dopamine, 2 to 20 µg/kg/min. Reason: Your patient's history and clinical presentation is consistent with cardiogenic shock. She has had chest pressure and shortness of breath for 2 days and is now significantly hypotensive with weak pulses. Because of its positive inotropic effect of increasing myocardial contractility, dopamine is the drug of choice for non-hypovolemic shock (eg, cardiogenic shock) and may improve perfusion. Typically, dopamine for cardiogenic shock is started at 2 µg/kg/min and titrated upwards as needed to improve blood pressure and perfusion. At doses of greater than 10 µg/kg/min, dopamine acts predominantly as a vasopressor, which results in systemic vasoconstriction. Clearly, nitroglycerin is contraindicated in any patient with shock; its potent vasodilatory effects would further lower the patient's blood pressure and worsen her condition. Amiodarone is not the drug of choice for this patient; it is given in a dose of 150 mg over 10 minutes for hemodynamically stable patients with wide or narrow-complex tachycardias that exceed 150 beats/min. Caution must be used if you consider giving a normal saline bolus; the coarse crackles in her lungs indicate pulmonary edema, which could easily be exacerbated by large fluid boluses. Her problem is heart failure, not hypovolemia. You are assessing the cardiac rhythm of a woman with respiratory distress. The rhythm is irregularly irregular with a rate of 120 beats/min. The QRS complexes measure 0.10 seconds in duration, the P wave to QRS ratio is 1:1, and the P waves vary in shape. This cardiac rhythm is MOST likely: A: atrial fibrillation. B: atrial flutter with aberrancy. C: multifocal atrial tachycardia. D: a wandering atrial pacemaker. C: multifocal atrial tachycardia. Reason: In multifocal atrial tachycardia (MAT), the pacemaker of the heart moves within various areas of the atria. MAT is characterized by a ventricular rate that is greater than 100 beats/min. MAT is irregularly irregular, with variation between R-R intervals based on the site of the pacemaker for that particular complex. P waves are present, upright, and precede each QRS complex; however, the shapes of the P waves vary as an indication of their different sites of origin. The P-R interval generally measures between 0.12 and 0.20 seconds, but also varies slightly based on the origin of the particular complex. Atrial fibrillation (A-Fib) is also an irregularly irregular rhythm; however, there are no discernable P waves. A wandering atrial pacemaker essentially contains all the components of MAT; unlike MAT, however, the ventricular rate is typically less than 100 beats/min. Atrial flutter (A-Flutter) has characteristic flutter waves (F waves) that resemble a saw tooth. If accompanied by aberrancy, A-flutter has QRS complexes that are greater than 0.12 seconds in duration, which indicates abnormal (aberrant) ventricular conduction. On the 12-lead ECG, the high lateral wall of the left ventricle is viewed by leads: A: III and aVF. B: I and aVL. C: V1 and V2. D: V5 and V6. B: I and aVL Reason: Leads V1 and V2 view the interventricular septum. Leads V3 and V4 view the anterior wall of the left ventricle. Leads V5 and V6 view the low lateral wall of the left ventricle. Leads I and aVL view the high lateral wall of the left ventricle. Leads II, III, and aVF view the inferior wall of the left ventricle. Lead V4R views the right ventricle. A 59-year-old woman presents with a regular, narrow-complex tachycardia at a rate of 180 beats/min. She is conscious and alert, but complains of chest discomfort and has a blood pressure of 86/56 mm Hg. In addition to giving her supplemental oxygen, you should: A: administer 150 mg of amiodarone over 10 min. B: have her chew and swallow 325 mg of aspirin. C: give her up to 3 sublingual doses of nitroglycerin. D: administer 12 mg of adenosine rapid IV push. B: have her chew and swallow 325 mg of aspirin Reason: A regular, narrow complex tachycardia at a rate greater than 150 beats/min is consistent with supraventricular tachycardia (SVT). Although the patient is conscious and alert, she is complaining of chest discomfort and is hypotensive. Since she could be experiencing an acute coronary syndrome (ACS), you should instruct her to chew and swallow up to 325 mg of aspirin. Aspirin should be given to any patient suspected of experiencing an ACS, provided there are no contraindications (eg, allergy); it will not affect her blood pressure. Nitroglycerin, however, may exacerbate her hypotension and should be avoided. You can consider administering adenosine; however, the initial dose is 6 mg rapid IV push. Amiodarone, in a dose of 150 mg over 10 minutes, is appropriate for patients with hemodynamically stable wide-complex tachycardias (ie, V- Tach). Closely monitor this patient and be prepared to perform synchronized cardioversion. Assessment and treatment of a responsive adult with a suspected acute coronary syndrome (ACS) might include all of the following, EXCEPT: A 145-pound man requires a dopamine infusion at 15 µg/kg/min for severe hypotension. You have a premixed bag containing 800 mg of dopamine in 500 mL of normal saline. If you are using a microdrip administration set (60 gtts/mL), how many drops per minute should you deliver to achieve the required dose? A: 48 B: 42 C: 30 D: 36 D: 36 We have an expert-written solution to this problem! Ventricular ejection fraction is defined as the: A: percentage of blood in the ventricle pumped out during a contraction. B: volume of blood pumped into the left ventricle from the left atrium. C: amount of blood pumped out from either ventricle per contraction. D: amount of blood pumped from either ventricle each minute. A: percentage of blood in the ventricle pumped out during a contraction. Reason: Ejection fraction (EF) is the percentage of blood that is pumped from the ventricle per contraction. The total volume of blood pumped out of the ventricle per contraction is called the stroke volume (SV). If the ventricle contains 100 mL of blood before a contraction, but only ejects 55 mL when it contracts (SV), the ejection fraction is 55% (100 mL × 0.55 = 55 mL). Ejection fraction should be at least 65% in the adult. Cardiac output (CO) is the volume of blood ejected from the left ventricle each minute, and is calculated by multiplying the stroke volume by the heart rate; in the adult, this is typically 5 to 6 L/min You arrive approximately 8 minutes after a 51-year-old male collapsed at a family event. After determining that he is unresponsive and apneic, you should: A: begin CPR, starting with chest compressions. B: immediately assess the patient's cardiac rhythm. C: assess for a carotid pulse for 5 to 10 seconds. D: give 2 rescue breaths and check for a pulse. C: assess for a carotid pulse for 5 to 10 seconds. Reason: After determining that an adult patient is unresponsive and apneic, you should assess for a carotid pulse for at least 5 seconds but no more than 10 seconds. If the patient has a pulse, open the airway and provide rescue breathing. If the patient does not have a pulse, begin CPR (starting with chest compressions), then open the airway and give 2 rescue breaths. Assess the patient's cardiac rhythm as soon as a monitor/defibrillator is available. ECG indicators of Wolff-Parkinson-White (WPW) syndrome include: A: tall P waves, QT interval prolongation, and tachycardia. B: narrow QRS complexes and peaked T waves. C: delta waves, flattened T waves, and bradycardia. D: short PR intervals, delta waves, and QRS widening. D: short PR intervals, delta waves, and QRS widening Reason: Wolff-Parkinson-White (WPW) syndrome is a condition in which accessory pathways—called the bundle of Kent—bypass the atrioventricular (AV) node, causing the ventricles to depolarize earlier than normal (preexcitation). Because the normal delay at the AV node does not occur, the PR intervals in patients with WPW are usually less than 0.12 seconds (120 ms). When conduction occurs down the AV node and simultaneously along the bundle of Kent in an anterograde fashion, the two waves of depolarization meet (fusion). This manifests on the ECG as a delta wave— slurring or notching at the beginning of the QRS complex—which may cause QRS widening. The bundle of Kent is a potential site for a reentry circuit because it allows continued transmission of an electrical impulse from the atria to the ventricles. Therefore, patients with WPW are prone to reentry tachycardias—most notably, AV reentry supraventricular tachycardia (SVT). A patient's medication regimen includes fluoxetine, Toprol, Proscar, lansoprazole, and Klonopin. Which of these medications is used to treat cardiovascular disorders? A: fluoxetine B: Toprol C: lansoprazole D: Proscar B: Toprol Reason: Toprol (metaprolol) is a commonly prescribed beta-blocker used to treat various cardiovascular conditions, including hypertension and tachydysrhythmias. Proscar (finasteride) is used to treat benign prostatic hyperplasia (BPH). Fluoxetine (Prozac) is a selective serotonin reuptake inhibitor (SSRI) antidepressant. It is used to treat conditions such as depression, generalized anxiety disorder, and obsessive-compulsive disorder (OCD). Lansoprazole (Prevacid)—a proton pump inhibitor—is used to treat conditions such as heartburn, acid reflux disease, and ulcers. Clonazepam (Klonopin) is a benzodiazepine sedative-hypnotic; it is used to treat anxiety. You are transporting a 62-year-old male who called EMS because of nausea and diarrhea. His past medical history includes high cholesterol, for which he takes Lipitor; he denies any other medical history. His blood pressure is 132/78 mm Hg, pulse is 68 beats/min, and respirations are 16 breaths/min. He is receiving oxygen via nasal cannula and has a patent IV line established. He has been in a normal sinus rhythm, but is now experiencing occasional premature ventricular complexes (PVCs). After noting the PVCs, you should: A: reassess and continue monitoring him. B: administer 1.5 mg/kg of lidocaine. antidysrhythmic bolus (eg, lidocaine, amiodarone), followed by an infusion of that same drug. Side effects of atropine sulfate may include: A: hypotension. B: pupillary constriction. C: acute urinary retention. D: hypersalivation. C: acute urinary retention. Reason: Side effects of atropine sulfate may include thirst, dry mouth, pupillary dilation (mydriasis), tachycardia, hypertension, and urinary retention. Acute urinary retention is especially common in older men with benign prostatic hyperplasia (BPH), also known as an enlarged prostate gland. You and your team are performing CPR on a 70-year-old male. The cardiac monitor reveals a slow, organized rhythm. His wife tells you that he goes to dialysis every day, but has missed his last three treatments. She also tells you that he has high blood pressure, hyperthyroidism, and has had several cardiac bypass surgeries. Based on the patient's medical history, which of the following conditions is the MOST likely underlying cause of his condition? A: Drug toxicity B: Coronary thrombus C: Hypovolemia D: Hyperkalemia D: Hyperkalemia Reason: Although any of the listed conditions could be causing this patient's condition, the fact that he missed his last three dialysis treatments should make you most suspicious for hyperkalemia. Dialysis filters metabolic waste products from the blood in patients with renal insufficiency or failure. If the patient is not dialyzed, these waste products, including potassium and other electrolytes, accumulate to toxic levels in the blood. In addition to performing high-quality CPR, managing the airway, and administering epinephrine, your protocols may call for the administration of calcium chloride and sodium bicarbonate if hyperkalemia is suspected. Albuterol also has been shown to be effective in treating patients with hyperkalemia becauses it causes potassium to shift back into the cells; it can be nebulized down the ET tube or administered intravenously. Follow your local protocols regarding the treatment for suspected hyperkalemia. You are assessing a 50-year-old man with acute chest pressure, diaphoresis, and nausea. The 12-lead ECG tracing reveals 3-mm ST segment elevation in leads V3 through V6. This indicates: A: anterolateral injury. B: inferior injury. C: anteroseptal ischemia. D: lateral ischemia. A: anterolateral injury. Reason: Leads V1 and V2 view the interventricular septum. Leads V3 and V4 view the anterior wall of the left ventricle. Leads I, aVL, V5 and V6 view the lateral wall of the left ventricle. Leads II, III, and aVF view the inferior wall of the left ventricle. Myocardial ischemia manifests on the 12-lead ECG with ST segment depression and/or T-wave inversion, whereas myocardial injury manifests with ST segment elevation that is equal to or greater than 1-mm in two or more contiguous leads. Therefore, 3-mm ST segment elevation in leads V3 through V6 indicates injury to the anterior and lateral wall of the left ventricle (anterolateral injury). A 50-year-old woman is pulseless and apneic. Your partner and an emergency medical responder are performing well-coordinated CPR. After 2 minutes of CPR, the cardiac monitor reveals coarse ventricular fibrillation. You should: A: shock the patient three times with 360 monophasic joules. B: deliver a single shock and immediately resume CPR. C: defibrillate at once and then reassess the rhythm and pulse. D: assess for a carotid pulse for no longer than 10 seconds. B: deliver a single shock and immediately resume CPR. Reason: A single shock (360 monophasic joules or the biphasic equivalent) should be administered to the patient with V-Fib or pulseless V-Tach cardiac arrest. Immediately following this single shock, begin or resume CPR, starting with chest compressions. Assessing the patient's cardiac rhythm and pulse immediately following defibrillation causes an unnecessary delay in CPR, and delays in CPR have been directly linked to poor patient outcomes. Most patients who are defibrillated—especially if their arrest interval is prolonged—remain in V-Fib/pulseless V-Tach or convert to another non-perfusing rhythm (ie, asystole, PEA). Either way, the patient is still in cardiac arrest and needs immediate CPR. After 2 minutes of CPR, reassess the patient's rhythm, and if necessary, a pulse (if an organized cardiac rhythm appears), and repeat defibrillation (single shock) if indicated, followed immediately by CPR. You are assessing a middle-aged female who complains of chest discomfort. She is conscious, alert, and oriented. Her skin is diaphoretic. Her blood pressure is 122/72 mm Hg, her pulse rate is 120 beats/min, and her respirations are 20 breaths/min. On the basis of her chief complaint, which of your assessment findings is the MOST significant? A: Mental status B: Diaphoresis C: Elevated respiratory rate D: Pulse rate of 120 beats/min D: Pulse rate of 120 beats/min Reason: Your patient has signs and symptoms of an acute coronary syndrome (ACS)—a spectrum of cardiac diseases that includes unstable angina pectoris and acute myocardial infarction. In ACS, tachycardia increases also characterized by P waves of varying morphologies as well as varying PR intervals. A second- or third-degree AV block should be suspected when there are more P waves than QRS complexes. Cardioversion involves delivering a shock that is synchronized to occur during the: A: P wave. B: downslope of the T wave. C: upslope of the T wave. D: R wave. D: R wave. Reason: Cardioversion involves delivering a shock that is synchronized to occur during the R wave, which is when the heart is absolutely refractory. This prevents the shock from occurring during the relative refractory period (the downslope of the T wave). Depolarization that occurs during the relative refractory period may induce a non-perfusing ventricular dysrhythmia, such as pulseless V-Tach or V-Fib. Synchronized cardioversion is indicated for patients with supraventricular or ventricular tachycardia who have a pulse, but are hemodynamically unstable. A 35-year-old female experienced a syncopal episode shortly after complaining of palpitations. She was reportedly unconscious for less than 10 seconds. Upon your arrival, she is conscious and alert, denies any injuries, and states that she feels fine. She further denies any significant medical history. Her vital signs are stable and the cardiac monitor reveals a sinus rhythm with frequent premature atrial complexes. On the basis of this information, what MOST likely caused her syncopal episode? A: A brief episode of ventricular tachycardia B: Aberrant conduction through the ventricles C: Paroxysmal supraventricular tachycardia D: A sudden increase in cardiac output C: Paroxysmal supraventricular tachycardia Reason: Syncope (fainting) of cardiac origin is caused by a sudden decrease in cerebral perfusion secondary to a decrease in cardiac output. This is usually the result of an acute bradydysrhythmia or tachydysrhythmia. In this particular patient, the presence of frequent premature atrial complexes (PACs), which indicates atrial irritability, suggests paroxysmal supraventricular tachycardia (PSVT) as the underlying dysrhythmia that caused her syncopal episode. In PSVT, the heart is beating so fast that ventricular filling and cardiac output decrease, which results in a transient decrease in cerebral perfusion. Not all patients with PSVT experience syncope. Many experience an acute onset of palpitations and/or lightheadedness that spontaneously resolves. Which of the following 12-lead ECG findings signifies a left bundle branch block? A: QRS duration of 122 ms; terminal S wave in lead V6 B: QRS duration of 126 ms; terminal S wave in lead aVL C: QRS duration of 128 ms; terminal R wave in lead V1 D: QRS duration of 124 ms; terminal S wave in lead V1 D: QRS duration of 124 ms; terminal S wave in lead V1 Reason: A QRS duration of greater than 120 ms (0.12 seconds [3 small boxes]) signifies an intraventricular conduction delay (IVCD), such as a bundle branch block. A left bundle branch block (LBBB) is characterized by a QRS duration of greater than 120 ms and a terminal S wave in lead V1 (the second half of the QRS complex terminates in an S wave); terminal R waves are seen in leads I, aVL, and V6. A right bundle branch block (RBBB) is characterized by a QRS duration of greater than 120 ms and a terminal R wave in lead V1 (the second half of the QRS complex terminates in an R wave); terminal S waves are seen in leads I, aVL, and V6. Immediately after establishing a return of spontaneous circulation in a woman with ventricular fibrillation of short duration, you should: A: obtain a 12-lead ECG to assess for cardiac damage. B: assess her ventilatory status and treat accordingly. C: assess her blood pressure and treat if needed. D: establish vascular access and give amiodarone. B: assess her ventilatory status and treat accordingly. Reason: Your first action after establishing return of spontaneous circulation (ROSC) in a patient—regardless of his or her arrest rhythm and duration— is to assess the patient's ventilatory status. If the patient is not breathing or is breathing inadequately, provide ventilatory support. After assessing and managing airway and breathing, assess the patient's blood pressure and stabilize it if it is low. Airway and circulatory support are critical following ROSC; inadequate ventilation and/or hypotension following cardiac arrest may lead to a recurrence of cardiac arrest. Depending on your local protocols, IV amiodarone may be given following ROSC. After assessing and maintaining respiratory and circulatory functions, obtain a 12-lead ECG if time allows. If the patient remains comatose following ROSC, consider inducing therapeutic hypothermia. A 27-year-old female complains of palpitations. The cardiac monitor reveals a narrow-complex tachycardia at 180/min. She denies any other symptoms, and states that this has happened to her before, but it typically resolves on its own. Her blood pressure is 126/66 mm Hg, pulse is 180 beats/min, and respirations are 16 breaths/min. After attempting vagal maneuvers and giving two doses of adenosine, her cardiac rhythm and vital signs remain unchanged. You should: A: infuse 150 mg of amiodarone over 10 minutes, reassess her, and repeat the amiodarone if needed. B: transport at once, reassess her frequently, and perform synchronized cardioversion if necessary. C: administer 5 mg of midazolam and perform synchronized cardioversion starting with 50 joules. A: Dysphasia, confusion, left side hemiparesis, right side facial droop B: Decerebrate posturing, asymmetric pupils, hypertension, bradycardia C: Aphasia, lethargy, right side hemiparalysis, right side facial droop D: Dysarthria, confusion, right side hemiparesis, left side facial droop D: Dysarthria, confusion, right side hemiparesis, left side facial droop Reason: Acute ischemic strokes represent approximately 75% of all strokes. Each cerebral hemisphere controls functions on the contralateral (opposite) side of the body; therefore, sensory and motor deficits (ie, hemiparesis, hemiparalysis) are observed on the side of the body opposite the stroke. However, because the facial nerves do not decussate (cross as they leave the cerebral cortex, move through the brainstem, and arrive at the spinal cord), facial droop is typically observed on the ipsilateral (same) side as the stroke. Pupillary changes, if present, will also occur on the same side as the stroke because of optic nerve crossover in the brain. Other common signs of acute ischemic stroke include dysarthria (slurred speech), dysphasia (difficulty speaking or understanding), aphasia (inability to speak or understand), and mental status changes. In contrast to acute ischemic stroke, acute hemorrhagic stroke (caused by a ruptured cerebral artery) typically presents with more ominous signs, which include a sudden, severe headache that is followed by a rapid decline in level of consciousness. Because bleeding is occurring within the brain, intracranial pressure increases, resulting in signs such as decorticate (flexor) or decerebrate (extensor) posturing, asymmetric or bilaterally dilated pupils, and Cushing's triad (hypertension, bradycardia, abnormal respiratory pattern). The initial dose of diltiazem for a 165-pound patient is approximately: A: 19 mg. B: 17 mg. C: 25 mg. D: 22 mg. A: 19 mg. Reason: Diltiazem hydrochloride (Cardizem) is a calcium channel blocking drug that is used to treat rapid ventricular rates associated with atrial fibrillation or atrial flutter. It can also be used after adenosine to treat refractory reentry supraventricular tachycardia in hemodynamically stable patients. The initial dose of diltiazem is 0.25 mg/kg IV over 2 minutes; the average initial dose is 15 to 20 mg. It may be repeated in 15 minutes in a dose of 0.35 mg/kg IV over 2 minutes; the average second dose is 20 to 25 mg. A 165-pound patient weighs 75 kg. Therefore, the initial dose of diltiazem for a patient of this weight would be 18.75 mg (approximately 19 mg), and the second dose would be 26.25 mg (approximately 26 mg). In contrast to unstable angina, stable angina occurs when a patient: A: complains of chest pain at the same time of the day for more than 2 weeks. B: presents with chest pain or discomfort during periods of low oxygen demand. C: needs more than two nitroglycerin treatments to relieve his or her chest pain. D: experiences chest discomfort after a certain, predictable amount of exertion. D: experiences chest discomfort after a certain, predictable amount of exertion. Reason: Angina pectoris is a sign of coronary artery disease (CAD), and is the result of an imbalance in myocardial oxygen supply and demand. Stable angina occurs when the patient experiences chest pain or discomfort after a certain, predictable amount of exertion. Furthermore, the patient with stable angina typically knows what actions to take to relieve the pain (ie, rest, nitroglycerin). By contrast, unstable angina is characterized by noticeable changes in the frequency, severity, and degree of chest pain or discomfort. The patient experiences symptoms, which are often not relieved with rest and/or nitroglycerin, when myocardial oxygen demand is otherwise low (ie, sleep, rest). Unstable angina indicates advanced CAD; it is commonly referred to as preinfarction angina. A transmural myocardial infarction is defined as: A: an MI that involves the entire thickness of the left ventricular wall from endocardium to epicardium. B: multiple areas of myocardial necrosis confined to the inner one third to one half of the left ventricular wall. C: an MI that occurs without gross ST segment elevation or the presence of a pathologic Q wave. D: any area of infarcted myocardium that is caused by focal areas of acute coronary vasospasm. A: an MI that involves the entire thickness of the left ventricular wall from endocardium to epicardium Reason: A transmural myocardial infarction involves the entire thickness of the left ventricular wall from endocardium to epicardium; it is associated with ST- segment elevation and, eventually, the development of pathologic Q waves. A subendocardial infarction involves multiple areas of myocardial necrosis confined to the inner one third to one half of the left ventricular wall; subendocardial infarctions are also referred to as non-Q-wave infarctions. Myocardial ischemia caused by focal areas of spontaneous coronary vasospasm, which may lead to infarction, is called Prinzmetal's (variant) angina; the exact cause of this spontaneous coronary vasospasm is largely unknown. You are assessing a 59-year-old woman who complains of chest pressure. When you are looking at her list of medications, you note that she takes Vasotec. What type of medication is this? A: Parasympathetic blocker We have an expert-written solution to this problem! You and your team are performing CPR on a middle-aged male who presented with asystole. After 2 minutes of CPR, you reassess him and note that his cardiac rhythm has changed to ventricular fibrillation. You should: A: defibrillate and then resume CPR. B: assess for a carotid pulse for 5 seconds. C: defibrillate after 2 more minutes of CPR. D: make sure the leads are still attached. A: defibrillate and then resume CPR. Reason: CPR alone rarely, if ever, converts asystole—or any other cardiac arrest rhythm—to a perfusing rhythm. Furthermore, if one of the leads detaches from the patient's chest, you will more likely see something that resembles massive artifact, not ventricular fibrillation (V-Fib). If you see V- Fib on the cardiac monitor, defibrillate one time with 360 monophasic joules (or equivalent biphasic) and then immediately resume CPR, starting with chest compressions. Assessing for a carotid pulse in a patient who is clearly in V-Fib wastes time; it delays defibrillation and CPR. After 2 minutes of CPR, reassess the patient's cardiac rhythm; if V-fib is still present, defibrillate one time and immediately resume CPR. If you see an organized cardiac rhythm, assess for a pulse for at least 5 seconds but no more than 10 seconds, and then resume CPR if indicated. A 47-year-old male took two of his prescribed nitroglycerin tablets prior to calling EMS. When you arrive at the scene, the patient tells you that he has a throbbing headache and is still experiencing chest pain. Your MOST immediate suspicion should be that: A: his chest pain is probably not of a cardiac origin. B: permanent myocardial damage has already occurred. C: he is experiencing continued myocardial ischemia. D: his nitroglycerin is outdated or has lost its potency C: he is experiencing continued myocardial ischemia Reason: When a patient reports taking nitroglycerin (NTG) for chest pain, you should determine how many tablets or sprays he or she took, and whether or not the NTG relieved his or her pain. Failure of NTG to relieve cardiac- related chest pain can occur for one of two reasons—the pain is of extraordinary severity, such as that associated with acute myocardial infarction, or the NTG has been open too long and has lost its potency. Fresh, potent NTG has certain distinct side effects, including a throbbing headache, a burning sensation under the tongue, and a bitter taste. If the patent did not experience any of these side effects, chances are the drug was outdated or had lost its potency. However, if the patient experienced any of these side effects, but is still experiencing chest pain, you should suspect that he or she is experiencing continued myocardial ischemia and is in the process of having an acute myocardial infarction. A 12-lead ECG and other diagnostic tests (ie, echocardiography) are required to determine if permanent myocardial damage has occurred. In addition to CPR, the recommended treatment sequence for an unresponsive, apneic, and pulseless patient with a regular, wide-complex cardiac rhythm at a rate of 40 beats/min includes: A: transcutaneous cardiac pacing and 1 mg of epinephrine every 3 to 5 minutes. B: 1 mg of epinephrine every 3 to 5 minutes and 1 gram of calcium chloride. C: 40 units of vasopressin every 10 minutes and treating reversible causes. D: 1 mg of epinephrine every 3 to 5 minutes and treating reversible causes. D: 1 mg of epinephrine every 3 to 5 minutes and treating reversible causes Reason: Pulseless electrical activity (PEA) exists when an unresponsive, apneic, pulseless patient presents with a regular cardiac rhythm. Treatment for PEA includes immediate high-quality CPR with minimal interruptions, obtaining vascular access (IV or IO), 1 mg of epinephrine every 3 to 5 minutes, advanced airway management (ie, ET tube, multilumen or supraglottic airway), and assessing for and treating reversible causes (Hs and Ts). Vasopressin, in a one-time dose of 40 units, can be given to replace the first or second dose of epinephrine, but not both. There are insufficient data to recommend transcutaneous pacing (TCP) for patients with bradycardic PEA or asystole, and the routine use of calcium chloride during cardiac arrest is not recommended. Which of the following clinical presentations is MOST consistent with dissection of the ascending aorta? A: Acute tearing pain in between the scapulae, blood pressure discrepancy between arms, maximal pain severity from the onset B: Tearing abdominal pain unrelieved by analgesia, pulse deficit in the femoral arteries, lightheadedness, blood in the stool C: Gradual onset of chest pressure that increases in severity over time, hypotension, tachycardia, bilaterally weak radial pulses D: Sudden onset of lower back pain that radiates to the groin, urge to defecate, pain is constant and moderate in severity A: Acute tearing pain in between the scapulae, blood pressure discrepancy between arms, maximal pain severity from the onset Reason: Aortic dissection occurs when the layers of the aorta undergo destructive changes, resulting in an aneurysm (weakening and ballooning of the arterial wall). In dissection of the ascending aorta, the patient typically experiences an acute onset of ripping, tearing, or stabbing pain in the anterior chest or in between the scapulae. In some patients, it may be difficult to differentiate the pain of acute aortic dissection from that of acute myocardial infarction (AMI); however, a number of distinctive features may help. The pain of an AMI is often preceded by prodromal symptoms (eg, nausea, weakness, sweating). Although pain from an AMI is acute, it gradually intensifies over time and is typically described as a squeezing or pressure sensation. By contrast, the pain of aortic dissection is acute, is of maximal intensity from the onset, and is usually described