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cardiovascular system
early diastole - Ventricles relax. Semilunar valves close. Atrioventricular valves open. Ventricles fill with blood. mid diastole - Atria and Ventricles are relaxed. Semilunar valves are closed. Atrioventricular valves are open. Ventricles continue to fill with blood. late diastole - -SA node contracts -Atria Contract -Ventricles fill with more blood -Contraction reaches AV node systole - Contraction passes from AV node to Purkinje fibers and ventricular cells. Ventricles contract. Atrioventricular valves close. Semilunar valves open. Blood is pumped from the ventricles to the arteries. pre load - Represents volume The initial stretching of the cardiac myocytes prior to contraction Amount of blood entering the heart, filling ventricles afterload - Resistance heart must overcome to contract Systemic and pulmonary resistance cardiac contractability - Ability of the heart to change its force of contraction
Inotropic drugs heart rate - Calculated as the number of contractions of the heart in one minute and expressed in bpm (beats per minute) Chronotropic drugs cardiac output - Stroke Volume X Heart Rate Equals Cardiac Output NL=3.5-8 Liters/Min Stroke Volume=50-100 ml/beat tests of cardiovascular function - Assessment Pulses Capillary refill Auscultation Radiology Size and contour of heart and related structures Chest X-ray CT scan MRI Stress Testing Treadmill Thallium and Cardiolite scans Electrocardiogram Gives information on heart rate and rhythm (electrical activity) EKG - Ultrasound exam Examine anatomic structures and function
Stable Angina—Coronary Artery Claudication—PVD Unstable plaques that rupture with subsequent thrombosis may lead to more-severe ischemia and infarction (stroke) stable plagues - Have thick fibrous caps Partially block vessels Do not tend to form clots or emboli Unstable Plaques - Have thin fibrous caps Plaque can rupture and cause a clot to form May completely block the artery The clot may break free and become an embolus atherosclerosis evaluation and treatment - Evaluation Feeling pulses, listening for bruits, and checking tissue perfusion Doppler ultrasonography, nuclear scanning, and angiography Treatment Removing risk factors (eg., smoking cessation and lowering cholesterol) Restoring normal blood flow Catheterization Aneurysm - : is a localized dilation or outpouching of a vessel wall or a cardiac chamber Wall of artery weakens and stretches Risk of rupture and hemorrhage Risk of clot formation
true aneurysm - permanent dilation of an artery that forms when tensile strength of the arterial wall decreases false aneurysm - occurs when a blood vessel wall is injured, and the blood is contained by the surrounding tissues. thrombus - blood clot thromboembolus - A blood clot within the blood vessel that may obstruct blood flow in the vessel embolism - Obstruction of a blood vessel by a clot of blood or foreign substance peripheral arterial disease - Thromboangiitis Obliterans aka (Buerger disease) Raynaud Phenomenon and Disease Thromboangiitis Obliterans (Buerger Disease) - Is an inflammatory disease of the peripheral arteries accompanied by thrombi, inflammation, and vasospasm of arterial segments Tends to occur in young men who are heavy cigarette smokers Symptoms: pain and tenderness, thick and malformed nails, gangrene Treatment: stop smoking and inc. blood flow to LE Raynaud Phenomenom and Disease - -Both are characterized by attacks of vasospasm in the small arteries and arterioles of the fingers, and less commonly, the toes -Raynaud Phenomenon: is secondary to systemic disease such as pulmonary hypertension, cold environments -Raynaud Disease: is a primary vasospastic disorder of unknown origin where endothelial damage and platelet activation do play a role.
Secondary Hypertension - Refers to sustained increases in blood pressure that result from identifiable underlying systemic diseases renal vascular disease - decreased flow to the kidney results in persistent increases in RAA activity renal parenchyma disease - damage to glomeruli or tubules leads to increased RAA activity adrenocortical tumors - increased production of cortisol and mineralocorticoids (aldosterone) lead to sodium retention and potassium loss adrenomedullary tumors - increased production of catecholamines with dramatic increases in heart rate and peripheral resistance Hypertension Clinical Manifestations - Doesn't produce symptoms until vascular changes in heart, brain or kidneys occur Severe Manifestations Brain—CVA, TIA Retina—Blindness Heart—MI Kidneys—Proteinuria, edema, renal failure hypertension diagnosis - Abnormally high blood pressure measures on at least 3 different occasions from a person who has been at rest 5 minutes Other tests used to help identify or rule out causes orthostatic hypotension - -Refers to a decrease in both systolic and diastolic arterial blood pressure on standing -Symptoms: dizziness, blurred vision, syncope -Causes: drug action, prolonged immobility caused by illness, starvation, physical exhaustion -Elderly persons are very susceptible
disease of veins - Varicose Vein Chronic Venous Insufficiency Deep Vein Thrombosis Superior Vena Cava Syndrome varicose veins - -Is a vein in which blood has pooled, producing distended, tortuous, and palpable vessels -Causes: -Trauma to the veins that damages one or more valves -Gradual venous distention caused by a combination of standing for long periods. Chronic Venous Insufficiency - -Is inadequate venous return over a long period -Affect about 5% of adults in developing countries Symptoms -Chronic pooling of blood in the veins of the LE. Edema may extend to the knees -Any trauma or pressure can cause cell death and necrosis (venous stasis ulcers) Deep Vein Thrombosis risk factors, symtoms, diagnosis, treatment - Risk factors -Triad of Virchow (stasis of venous blood flow, endothelial injury, hypercoagulability) Symptoms -Pain to the site, warm to touch Diagnosis -Doppler ultrasonography Treatment -Anticoagulation: heparin, enoxaparin, respiratory
Examples: Hypertension Renal Failure Pulmonary diseases Anemia risk factors of CHF - Coronary artery disease Hypertension High cholesterol levels Advancing age Cigarette smoking Obesity Proteinuria Diabetes Compensatory Mechanisms of the Heart in CHF - Ventricular dilation and hypertrophy Increased sympathetic nervous system stimulation Renal response RBF decreases renin-angiotension aldosterone mechanism, Na and H20 retention left sided CHF - Shortness of breath Difficulty breathing, especially with exertion or lying down Wheezing Dry cough or cough that produces frothy or blood sputum Decreased urine output right sided CHF - Swollen ankles and feet Rapid weight gain due to fluid retention Abdominal pain and fullness
Swollen neck veins Frequent urination at night CHF clinical manifestations - General feeling of illness Severe fatigue and weakness Irregular or rapid HR Loss of appetite Nausea/vomiting Anxiety Irritability and restlessness Mental confusion Weight gain severe manifestations CHF - Pleural effusion Increased pressure in pleural capillaries Leakage of fluid from capillaries into pleural space. Arrhythmias Left ventricular thrombus Hepatomegaly Liver becomes congested with venous blood Leads to impaired liver function diagnosis CHF - History and physical exam CXR ECHO EKG Blood work Electrolytes Serum osmolarity
Pericardial Effusion - The accumulation of fluid in the pericardial cavity The fluid may be Serous effusion An exudate Serosanguineous Blood cardiac temponade - Fluid or blood in pericardial sac compression of heart Due to trauma, MI, Med. Bleed Inc. CVP, JVD, Shock, heart sounds inaudible ECHO, CT chest Treatment: Pericardial Window, Pericardiocentesis coronary artery disease - Any vascular disorder that narrows or occludes the coronary arteries Leading cause of death in US 1 out of every 5 deaths Death due to insufficient oxygen to heart muscle Risk and gender Men > 45 Women > 55 risk factor for CAD - Dyslipidemia Hypertension Smoking Diabetes mellitus Obesity Sedentary lifestyle
diagnosis of CAD - Ischemic disease often presents with dyspnea MI often presents with syncope, dyspnea, abdominal complaints, nausea & vomiting, and mental status changes Resting EKG often abnormal Noninvasive testing of choice depends on exercise tolerance Treatment of CAD - Treatment depends on the severity CAD is a chronic disease and requires lifelong care. Angioplasty or bypass surgery is NOT a "cure." Control/reduce of risk factors Percutaneous transluminal coronary angioplasty Coronary artery bypass surgery Drugs Relieve chest pain and complications of CAD Prevent blood clots from forming on plaques Lower cholesterol CANNOT clear blocked arteries stable angina - Stable Angina: symptoms occur only with exercise and are relieved with rest prinzmental angina - Prinzmetal's angina: results from vasospasm of coronary vessels without underlying atherosclerosis unstable angina - pain at rest acute coronary syndrome causes and triggers - Dysrhythmias Embolus Thrombosis
Inverted T waves Formation of Q waves acute coronary disease diagnosis - History and physical Blood CPK, Troponin Blood gas Electrolytes CBC Serial 12 lead ECG's CXR Angiogram ECHO Stress test acute coronary disease treatment - Oxygen Medications Antianginals Analgesics Thrombolytics Antiarrythmics Anticoagulant Treatment aimed at identified cause Reduce need to strain Provide comfort and support Assess and support lifestyle changes Close monitoring and reassessment for pain and other symptoms Cardiac rehabilitation
Cardiomyopathies causes and types - Group of diseases that primarily affect the myocardium itself Causes Due to remodeling caused by the myocardial and neurohumoral responses to ischemic heart disease and hypertension Due to infection, toxins, nutrition deficiency Types Dilated Hypertrophic Restrictive Valvular Defects - Each of the four valves can be defective Stenosis: valve will not open all the way; it is harder to force blood through it Regurgitation: valve will not close all the way; it leaks when it should be closed left side valvular disorders - Mitral valve disorders Mitral valve stenosis Mitral valve regurgitation Mitral valve prolapse Aortic valve disorders Aortic valve stenosis Aortic valve regurgitation mitral valve prolapse - Cusps of the mitral valve billow upward into the left atrium during systole. It is common Studies suggests an autosomal dominant inheritance pattern Many cases asymptomatic Regurgitation can occur Symptomatic MVP can cause palpitations related to dysrhythmias, tachycardia, light-headedness, syncope, fatigue
