Arrhythmia Identification

Course overview

Objectives Explain cardiac arrhythmia identification and interpretation List the various components of ECG complexes Content Information Covered 1 Cardiac arrhythmias 1 Approach to analysis 1 P wave 1 Configuration 2 Duration 3 Atrial rate and rhythm 2 PR interval PQ interval 3 QRS complex 1 Configuration 2 Duration 3 Ventricular rate and rhythm 4 ST segment 1 Contour 2 Elevation 3 Depression 5 QT interval 1 Duration 2 Implication of prolongation Relationship of P waves to QRS complexes 1 Consistent 2 Progressive prolongation 3 No relationship 7 T waves 8 U waves 2 Interpretation of the ECG 1 Origin of complex 2 Rate 3 Rhythm 4 Clinical significance Arrhythmias originating in the sinus node 1 Sinus bradycardia 2 Sinus tachycardia 3 Sinus arrhythmia 4 Sinus arrest Arrhythmias originating in the atria 1 Premature atrial complex 2 Atrial ectopic tachycardia 3 Re entrant tachycardia 4 Multifocal atrial tachycardia 5 Atrial flutter 6 Atrial fibrillation 7 Atrial flutter or atrial fibrillation with junctional rhythm 8 Atrial flutter or atrial fibrillation with pre excitation syndromes Arrhythmias originating within the AV junction 1 First degree AV block 2 Second degree AV block 1 Type I Wenckebach 2 Type II infranodal classical 3 Complete AV block third degree Arrhythmias sustained or originating in the AV junction 1 AV nodal re entrant tachycardia 2 AV reciprocating tachycardia 1 Narrow 2 Wide 3 Junctional escape rhythm 4 Premature junctional complex 5 Accelerated junctional rhythm 6 Junctional tachycardia Arrhythmias originating in the ventricles 1 Idioventricular rhythm 2 Accelerated idioventricular rhythm 3 Premature ventricular complex ventricular ectopic 1 R on T phenomenon 2 Paired couplets 3 Multiformed 4 Frequent uniform Rule of bigeminy pertaining to precipitating ventricular arrhythmias 5 Ventricular tachycardia 1 Monomorphic and polymorphic torsades 2 Ventricular fibrillation 6 Ventricular standstill 7 Asystole Abnormalities originating within the bundle branch system 1 Incomplete or complete 2 Right bundle branch block 3 Left bundle branch block Differentiation of wide QRS complex tachycardia 1 Potential causes 1 Supraventricular tachycardia with bundle branch block 2 Accessory pathways 2 Differentiation 1 Physical evaluation 1 Cannon A waves 2 Variable intensity of first heart tone 3 Beat to beat changes in blood pressure 2 ECG differences 1 Aberration as a result of premature atrial complex 1 Identify PAC in previous ST segment or T wave 2 Sudden change in rate with bundle branch aberration 3 Concealed retrograde conduction 4 Right bundle branch refractoriness may be time dependent 5 Compare with previous ECG when available 2 RBBB aberration V1 positive 1 Biphasic lead I with a broad terminal S wave 2 Triphasic QRS in V4 3 LBBB aberration V1 negative 1 Monophasic notched lead I 2 Slurred notched or RSr pattern in leads V4 V5 or V6 4 Concordant precordial pattern 1 Totally negative precordial pattern is diagnostic of ventricular tachycardia 2 Totally positive precordial pattern is suggestive of ventricular tachycardia 5 Preexisting bundle branch block prior to onset of tachycardia by history 3 Other considerations 1 When in doubt 1 Cardioversion when hemodynamic state is compromised or changing Never use verapamil If hemodynamic state is stable consider lidocaine 2 Pitfalls 1 Age is not a differential 2 Slower rates may present with stable hemodynamics 3 Preexisting bundle branch block prior to onset of tachycardia 3 Regularity 1 Monomorphic ventricular tachycardia and supraventricular tachycardia are usually very regular and SVT is frequently faster 2 Polymorphic ventricular tachycardia is irregular 10 Pulseless electrical activity 1 Electrical mechanical dissociation 2 Mechanical impairments to pulsations or cardiac output 3 Other possible causes 11 Other ECG phenomena 1 Accessory pathways 2 Pre excitation phenomenon 3 Aberration versus ectopy 12 ECG changes due to electrolyte