RELIAS DYSRHYTHMIA BASIC B 35 QUESTIONS WITH ANSWERS Course Relias dysrhythmia Institution, Lecture notes of Engineering Mathematics

Download RELIAS DYSRHYTHMIA BASIC B 35 QUESTIONS WITH ANSWERS Course Relias dysrhythmia Institution and more Lecture notes Engineering Mathematics in PDF only on Docsity! 1 BY: AUGUSTO TEODORO, JR., MD, FPCEM REFERENCE:  AHA Advanced Cardiovascular Life Support Pro- vider Manual, 2011  2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science  Dysrhythmia for Monitor Technicians, Flexed  Lewis, KM, Sensible Analysis of the 12-Lead ECG. Delmar Thomson Learning. 2000  Atwood, et al. Introduction to Basic Cardiac Dysrhythmias 4th Ed. Jones and Bartlett Learn- ing. 2011 no te s TOPIC ______________ PAGE C1: ANATOMY and PHYSIOLOGY...……………………. 2 C2: ELECTROCARDIOLOGY The Heart’s Conduction System ………………. 3 ECG Recording ………….……………………………. 4 ECG Waveforms ………………………………………. 5 10-Step Rhythm Analysis/Interpretation …. 6 C3: SINUS RHYTHMS …………..……………………………. 7 C3: ATRIAL RHYTHMS ………….……...………………….. 8 C4: JUNCTIONAL RHYTHMS …………………………….. 9 C5: ATRIOVENTRICULAR BLOCKS …………………….. 10 C6: VENTRICULAR RHYTHMS ……………………………. 11 C7: PACEMAKERS/OTHERS ....………………………….. 12 CX: ACUTE MYOCARDIAL INFARCTION……………… 13 CXX: RESUSCITATION/TREATMENT………………….. 14 CXXX: SUMMARY of DYSRHYTHMIA RECOGNITION 15 (REVISED APRIL 2014) 2 ANATOMY of the HEART CHAMBERS and VALVES of the HEART Right atrium (RA) Left atrium (LA) Mitral valve (MV) aka Bicuspid valve Tricuspid valve (TV) Left ventricle (LV) Right ventricle (RV) Interventricular septum Pulmonary Valve (PV) (not shown) Aortic Valve (AV) (not shown) ELECTRICAL CONDUCTION SYSTEM Sino-atrial node (SA node) Internodal and interatrial tracts Atrioventricular node (AV node) Bundle of His Left and right bundle branches Purkinje fibers FLOW OF BLOOD From the body (DEOXYGENATED BLOOD) Inferior and superior vena cava Right atrium Tricuspid valve Right ventricle Pulmonary valve Pulmonary arteries (DEOXYGENATED BLOOD) Lungs (gas exchange) Pulmonary veins (OXYGENATED BLOOD) Left atrium Mitral valve (aka bicuspid valve) Left ventricle Aortic valve Aorta Systemic circulation (OXYGENATED BLOOD) CHAMBERS ABBREVIATION right atrium RA right ventricle RV left atrium LA left ventricle LV VALVES CONNECTS Tricuspid RA and RV Pulmonary RV and Pulmonary artery Mitral(Bicuspid) LA and LV Aortic LV and Aorta CIRCULATION  PULMONARY CIRCULATION: When the RIGHT VENTRICLE pumps DEOXYGENATED BLOOD into the PULMONARY ARTERY (via pulmonary valve) and back to the heart  SYSTEMIC CIRCULATION: When the LEFT VENTRICLE pumps OXYGENATED BLOOD into the AORTA (via aortic valve) and back to the heart HEMODYNAMIC PARAMETERS  Heart rate—number of beats per minute  Stroke volume—amount of blood ejected from LV with every contraction (70mL) PRELOAD— volume of blood present in the ventricles after passive and active filling prior to contraction AFTERLOAD—resistance against which the ventricles must pump to eject blood  Cardiac output—amount of blood ejected from LV in one minute STARLING’s LAW OF THE HEART When the diastolic filling of the heart (EDV) is increased or decreased with a given vol- ume; the force of contraction increases or decreases with this volume Heart rate X stroke volume = cardiac output 70beats X 70mL = 4900 mL = _5L___ minute beat minute minute REMEMBER: 4 CHAMBERS —RA, LA, RV, LV 4 VALVES —T.P.M.A. 4 VESSELS —SVC/IVC, —Pulmonary artery —Pulmonary vein —Aorta Phases of Normal Electrical Activity: POLARIZATION: Phase of readiness DEPOLARIZATION: Phase of contraction (stimulation, excitation) REPOLARIZATION: Phase of relaxation 5 ECG WAVEFORM COMPONENTS T WAVE  Represents ventricular repolarization or relaxation  NV: <5mm in amplitude MEASURING TIME and AMPLITUDE Width (horizontal lines) duration or time (in seconds) Height (vertical lines) height or amplitude (in mm or mV) 1 small box 0.04 sec 1 mm or 0.1mV 1 big box 0.2sec 5mm or 0.5mV 5 small boxes 1 second 5 big boxes = 25 small boxes 1 minute 300 big boxes W A V EF O R M S N O R M A L V A LU ES A B N O R M A LI T IE S P w av e 0 .1 0 se c o r 2 .5 s m al l  Ju n cti o n al P ( H id d en o r in ve rt ed P ), A tr ia l P (n o tc h ed , t al l a n d p ea ke d , fl at , d ip h as ic P ) Q R S co m p le x N ar ro w Q R S: 0 .0 6 -0 .1 2 se c o r 1 .5 — 3 s m al l  W id e Q R S is v en tr ic u la r (I V s e p tu m a n d p u rk in je fi b er s) in o ri gi n u n le ss p ro ve n o th er w is e; B u n d le b ra n ch b lo ck s (B B B ) ca u se w id en in g o f th e Q R S T w av e U p ri gh t, < 5 m m M yo ca rd ia l i sc h e m ia , A M I, P o ta ss iu m e xc e ss (h yp er ka le m ia ) P R In te rv al 0 .1 2 -0 .2 0 s ec Sh o rt en ed in W P W , J u n cti o n al /A tr ia l r h yt h m s ST s eg m en t Is o el ec tr ic >1 m m e le va ti o n is p o ss ib le S TE M I QRS COMPLEX  Electrical current generated by ventricular depolarization  Q wave—first negative deflection (<25% of R wave amplitude)  R wave—first positive deflection  S wave—negative deflection following R wave  NV: 0.06-0.12 sec = 1.5 to 3 small squares ST SEGMENT  Represents early repolarization  Begins with the end of QRS complex and ends with the onset of T wave  Evaluated to see if elevated or depressed  Usually not depressed >0.5mm in any lead  NV: isoelectric PR INTERVAL  Start of P wave to begin- ning of QRS complex  Represents the length of time required for the atria to depolarize and the de- lay of impulse through the AV junction  NV: 0.12-0.20 sec = 3-5 mm QT INTERVAL  Represents total ventricular activity  Measured from the beginning of QRS to the end of the T wave  NV: 0.36-0.44 sec = 8-10 mm P WAVE  Represents atrial depolarization  Normally upright in Lead II  If normal in size and shape, assumed to be sinus in origin  NV: 0.10 sec = 2.5 small squares TIME A M P LI T U D E 6 10 STEP ANALYSIS OF RHYTHM INTERPRETATION     - - -  -  - -  - - - -   - -      -            Caliper Method Paper and Pencil Method 20 small 30 0 15 0 10 0 75 1 second 1 second 1 second 1 second 1 second 1 second 4 big boxes boxes 6 SECOND STRIP METHOD FORMULA Small Box 1500/#small between R-R Sequence R-R 300-150-100-75-60… Big box 300/#big between R-R 6-second # of R waves in 6s X10 PR Interval Normal 0.12-0.20sec OR 3-5 small  1O AVB prolonged but fixed PRI 2O AVB Type I progressive lengthening of PRI until QRS is dropped 2O AVB Type II fixed PRI then dropped QRS 3O AVB no relation between P wave and QRS complexes Shortened WPW, R atrial, Junctional rhythms P waves Sinus Upright and rounded (2.5 smallor 0.10 sec) Atrial Upright but abnormal looking Junctional Inverted before/after QRS or absent Ventricular No P waves QRS Complex Duration Normal/Narrow (Supraventricular) <0.12 sec or <3 small Wide (Ventricular) >0.12sec P wave and QRS complex # P = # QRS e.g. NSR # P < # QRS e.g., Junctional # P > # QRS e.g. 2O AVB 7 Sino-Atrial Node is the DOMINANT pacemaker of the heart Symptomatic Sinus bradycardia: treated with atropine or TCP Sinus tachycardia: search and treat the underlying cause (e.g. fever, pain) SINUS RHYTHMS Normal Sinus Rhythm Rhythm: Regular Rate: 60-100 beats per minute P: uniform and upright in appearance PRI: 0.12-0.20 sec; consistent QRS: <0.12 sec Sinus Bradycardia Rhythm: Regular Rate: <60 beats per minute P: uniform and upright in appearance PRI: 0.12-0.20 sec; consistent QRS: <0.12 sec Sinus Tachycardia Rhythm: Regular Rate: >100 beats per minute P: uniform and upright in appearance PRI: 0.12-0.20 sec; consistent QRS: <0.12 sec Sinus Arrhythmia Rhythm: Irregular Rate: 60-100 beats per minute P: uniform and upright in appearance PRI: 0.12-0.20 sec; consistent QRS: <0.12 sec Sinus Arrest SA node fails to fire resulting in the absence of P-QRS-T. The next beat after the pause is unpredictable. Sinus Block SA node initiates the impulse, but the propagation over atrial tissue is blocked, so the atria are not depolarized, therefore there is no P wave and QRS complex. P-P or R-R interval is undis- turbed (predictable) SINUS Sinus Rhythm Sinus Tachycardia Sinus Bradycardia Sinus Arrhythmia Sinus exit block Sinus arrest Rhythm Regular Regular Regular Irregular Regular except for the event Regular except for the event Rate 60-100 >100 <60 60-100 P (+)/QRS (+)/QRS (+)/QRS (+)/QRS (+)/QRS (+)/QRS PRI 0.12-0.20sec 0.12-0.20sec 0.12-0.20sec 0.12-0.20sec 0.12-0.20s 0.12-0.20s QRS <0.12sec <0.12ses <0.12sec <0.12sec Event Missing PQRST but P-P or R-R interval undisturbed Missing PQRST but P-P or R- R interval disturbed PAUSE PAUSE 10 ATRIOVENTRICULAR BLOCKS (AVB) First Degree AV Block Rhythm: regular Rate: may be normal, fast or slow P waves: normal sinus PRI: >0.20 sec; fixed and prolonged QRS: <0.12 sec; NO DROPPED QRS *May progress to 2nd or 3rd degree AV block Second Degree AV Block Type 1 (Wenckebach) Rhythm: P-P is regular, R-R irregularity is cyclical Rate: usually slow but maybe normal P waves: normal sinus (more Ps than QRS) PRI: progressive delay following P wave until QRS is DROPPED QRS: <0.12 sec; misses a QRS Second Degree AV Block Type 2 (TWO IS TROUBLE) Rhythm: regular Rate: usually slow P waves: normal sinus (more Ps than QRS) PRI: fixed (duration can be normal or prolonged) QRS: <0.12 sec; misses a QRS (DROPPED QRS) Greater risk of progressing to complete heart block Third Degree AV Block (Complete Heart Block) Rhythm: regular P-P and R-R but there are 2 independent rhythms Rate: P-P 60-100 R-R 40-60 if junctional, 20-40 if ventricular P waves: normal sinus P with NO RELATIONSHIP to QRS PRI: not measurable QRS: <0.12sec if from the junction >0.12sec if from a ventricular pacing site PRI DURATION EXAMPLE Normal, fixed <0.20s 2nd degree AVB type II Prolonged, fixed >0.20s 1st degree AVB 2nd degree AVB type II Lengthens progressively Increasing delay after P wave on each cycle 2nd degree AVB type I  AV blocks are due to a sick AV node  The impulse originates in the SA node but has trouble getting through the AV node to the ventricles  The P-P intervals are regular in all AV blocks  A dropped QRS means 2 or more P waves with no QRS in between  The QRS duration will tell the level of block which could be above or below the bundle of His  AV blocks need to be closely monitored especially 2nd degree Type II because it may deteriorate to complete heart block or 3rd degree AV block. In both cases TCP must be done if the patient is symptomatic. 1O A V B 2O A V B T yp e 1 2 O A V B T yp e 2 3 O A V B F F V V ? NO YES IRREG REG DROPS QRS? VENTRICULAR RHYTHM? FIXED/CONSTANT VARIABLE 1O AVB 2O AVB Type II 2O AVB Type I 3O AVB Q1 Q2 (Looks like a sinus rhythm BUT PRI is prolonged) P P P P P P P P P P P P Treatment options: If asymptomatic: no treatment If symptomatic with slow HR: Atropine TCP Usually, if 20 AVB Type II or 30 AVB is present , TCP is the treatment of choice DROPPED QRS X DROPPED QRS X DROPPED QRS X P P P P P P P P 11 VENTRICULAR MECHANISM PVC IVR/Ventricular Escape Rhythm Accelerated VER Ventricular Tachycardia (VT) Ventricular Fibrillation (VF) Asystole Rhythm NOT A RHYTHM regular regular regular chaotic, disorganized none Rate 20-40 40-100 >100 - none P waves none none none none none none PRI not measurable not measurable not measurable not measurable none none QRS wide and bizarre wide and bizarre wide and bizarre wide and bizarre not identifiable - T wave opposite direction of QRS opposite direction of QRS opposite direction of QRS opposite direction of QRS not identifiable - PVCs Bigeminy: every other beat is a PVC Trigeminy: every third beat is a PVC Quadrigeminy: every 4th beat is a PVC Salvo: 3 or more consecu- tive PVC’s (aka short run of VT or burst) Unifocal: identical PVCs that originate from a single ectopic pacemaker Multifocal: non-identical PVCs that originate from different ectopic pacemaker sites in the ventricle Couplet or pair: 2 PVCs in a row Monomorphic: identical Polymorphic: non-identical ESCAPE BEAT PULSELESS RHYTHMS:  Asystole  Agonal rhythms  VF  VT (may produce a pulse)  PEA Premature Ventricular Complex (may trigger VF or VT if R wave of PVC hits P’ waves: none the T wave of the preceding beat = R on T) PRI: none QRS: premature, wide and bizarre (>0.16 sec) Ventricular Escape Beat (SA node and junction fail to fire) P’ waves: none on the escape beat PRI: not applicable QRS: wide and bizarre Ventricular Escape Rhythm/Idioventricular Rhythm (IVR) Rhythm: regular Rate: 20-40 beats per minute P’ waves: none PRI: not applicable QRS: wide and bizarre Accelerated Ventricular Rhythm Rhythm: regular Rate: 40-100 beats per minute P’ waves: none PRI: not applicable QRS: wide and bizarre Ventricular Tachycardia Rhythm: usually regular Rate: >100-300 beats per minute P’ waves: none PRI: not measurable QRS: wide and bizarre Ventricular Fibrillation (pulseless) P’ waves: none PRI: not measurable QRS: not identifiable Torsade de Pointes P’ waves: none PRI: not measurable QRS: wide and bizarre that rotate from a negative to a positive deflection Asystole (Flatline) P’ waves: may or may not be present PRI: not measurable QRS: absent or occasional escape beats CHAOTIC, DISORGANIZED, NO IDENTIFIABLE PQRST STABLE Ventricular Tachycardia: may be treated with Amiodarone 150 mg over 10 minutes (LD) UNSTABLE Monomorphic Ventricular Tachycardia is treated with SYNC cardioversion VENTRICULAR FIBRILLATION is a life-threatening arrhythmia that needs early defibrillation 12 PACEMAKERS and OTHERS Produces a sharp narrow deflection called a spike or pacemaker artifact. Spike immediately precedes the chamber paced. If cap- tured, the waveform will follow. ATRIAL PACED: The sharp narrow spikes precedes the P wave VENTRICULAR PACED: The sharp narrow spikes pre- cede the QRS complex RATE PACEMAKER 20-40 40-60 60-100 >100 SINUS BRADY NORMAL TACHY JUNCTIONAL RHYTHM ACCELERATED TACHY VENTRICULAR RHYTHM ACCELERATED ACCELERATED TACHY KEY WORDS and ASSOCIATIONS: Atrial flutter: saw-tooth/picket fence Junctional P: inverted before, during, after QRS Premature beat: early abnormal beat then a pause Escape beat: a pause then an abnormal beat Retrograde conduction: inverted waveform 20 AVB Type I: PRI lengthens progressively then missed QRS 20 AVB Type II: fixed PRI then missed QRS 30 AVB: no relationship between atrial and ventricular beats P wave: atrial depolarization QRS: ventricular depolarization T wave: ventricular repolarization RHYTHMS THAT SHOULDN’T BE MISSED NOR MISDIAGNOSED ATRIAL FLUTTER NORMAL SINUS RHYTHM BIGEMINY SUPRAVENTRICULAR TACHYCARDIA TORSADES DE POINTES VENTRICULAR TACHYCARDIA BUNDLE BRANCH BLOCK VENTRICULAR FIBRILLATION ASYSTOLE VENTRICULAR PACED ST SEGMENT ELEVATION