Ventricular Arrhythmias Terry White, RN, EMT-P

Analyze the Rhythm

Premature Ventricular Complexes (PVCs) u Definitions u Early depolarization of the ventricles u Occur as a result of automaticity or reentry u A PVC is a characteristic of an underlying ECG rhythm u PVC is not the name of a dysrhythmia

Premature Ventricular Complexes u Causes u Hypoxia u Myocardial Ischemia u Electrolyte Imbalance u Digitalis Toxicity u Stimulants u Chronic Heart Disease (CHF, COPD)

Premature Ventricular Complexes (PVCs) u Characteristics u Complex is earlier than expected u Wide QRS (wide is not always ventricular) u OFTEN has a compensatory pause u Usually irregular u Not preceded by a P wave u T wave opposite deflection u May or may not result in perfused beat

Premature Ventricular Complexes (PVCs) u More Terms to Know u Unifocal, Multifocal u R on T Phenomenon u Bigeminy, Trigeminy, Quadrigeminy, Couplet

Premature Ventricular Complexes (PVCs) u PVCs are not always dangerous u Common for some people u Consider treating PVCs if: u >6/minute associated with: u Severe Chest pain u Hypotension, Decreased Perfusion u Shortness of Breath

Premature Ventricular Complexes (PVCs) u Treat PVCs if consistently see any of the following with other symptoms: u Multifocal u Ventricular Couplets u Runs of Ventricular Tachycardia u R on T Phenomenon (Malignant PVCs)

Premature Ventricular Complexes (PVCs) u Management (Rate <60) u Oxygen & Ventilation are initial treatments for ALL ectopic beats u ECG Monitor, IV NS TKO u assess the underlying rhythm u Treat like bradycardia u Atropine u TCP u Dopamine

Premature Ventricular Complexes (PVCs) u Management (Rate >60) u Oxygen & Ventilation are initial treatments for ALL ectopic beats u ECG Monitor, IV NS TKO u assess the underlying rhythm u If symptomatic (see previous):

Premature Ventricular Complexes (PVCs) u Management (Rate >60) u Lidocaine u IV Bolus, mg/kg u Infusion, 1 - 4mg/min u Repeat IV push mg/kg every 5 minutes to 3 mg/kg max u Increase Infusion 1mg/min for every 1mg/kg IV bolus given

Premature Ventricular Complexes (PVCs) u Management (Rate >60) u Procainamide u 20 mg/min IV until: u PVCs suppressed u 17 mg/kg given u Hypotension occurs u QRS widens by 50% or more u Continuous infusion at mg/min

Premature Ventricular Complexes (PVCs) u Management (Rate >60) u Bretylium u IV push, 5 mg/kg slowly u Infusion, mg/min u Used less frequently today due to supply shortage

Analyze the Rhythm

Idioventricular Rhythm u Causes u Myocardial ischemia u Hypoxia u High vagal tone u Drug effects

Idioventricular Rhythm u Characteristics u A ventricular focus takes over as an escape pacemaker site u Rate bpm u Wide QRS complexes u No P waves

Idioventricular Rhythm u Management u Slow rate will probably decrease cardiac output u Usually a later and often pre-terminal rhythm u If symptomatic, treat as unstable bradycardia u Do NOT give Lidocaine or other ventricular antidysrhythmics!!!!!!!

Analyze the Rhythm

Accelerated Idioventricular Rhythm u Characteristics u Like Idioventricular rhythm except for rate u Rate, greater than 40 bpm but less than 100 bpm

Accelerated Idioventricular Rhythm u Management u Patient may maintain adequate cardiac output u Identify underlying cause and treat!!! u Monitor cardiac output and perfusion u Often a late and pre-terminal rhythm u Do NOT give Lidocaine or other antidysrhythmics!!!!!!!

Analyze the Rhythm

Ventricular Tachycardia (VT) u Causes u Myocardial ischemia u Hypoxia u Electrolyte imbalance u Digitalis toxicity u Myocardial trauma

Ventricular Tachycardia (VT) u Characteristics u Pacemaker site u Irritable ventricular focus takes over as pacemaker site, OR u May result from multiple ventricular foci attempting to become pacemaker site u Complexes look similar to PVCs u May see P waves before complexes but uncommon u Rate, usually between 100 and 250 bpm

Ventricular Tachycardia (VT) u Complications u Can decrease cardiac output u Increases cardiac workload u Decreases coronary perfusion u Can quickly deteriorate into V-fib

Ventricular Tachycardia (VT) u Types u Monomorphic u QRS complexes all have same morphology u Polymorphic u QRS complexes have more than one morphology u “Torsades de Pointes” u “Twisting of the points” u Usually > 200 bpm u Susceptible if slow repolarization (long QT)

Ventricular Tachycardia (VT) u Treatment of Stable and Unstable u Oxygen, Ventilations, Assess Pulse u ECG Monitor u If unstable, proceed to synchronized cardioversion u IV NS TKO u Determine monomorphic vs polymorphic u If wide complex of unknown origin, attempt 12 lead ECG to determine

Ventricular Tachycardia Treatment: Monomorphic u Treatment of Stable (limit to one antidysrhythmic) u procainamide 20 mg/min IV u avoid if poor cardiac function u amiodarone 150 mg slow IV (15 mg/min) u lidocaine 1.0 mg/kg IV (max 3.0 mg/kg) u Begin with mg/kg poor cardiac function u Follow with lidocaine infusion, mg/min u synchronized cardioversion

Tachycardia: Wide Complex (VT) Polymorphic (Torsades) u Treatment (limit to one antidysrhythmic) u Normal QT u Lidocaine, mg/kg IV (max 3.0 mg/kg), mg/kg q 5 min to max 3 mg/kg u Amiodarone, 150 mg slow IV (15 mg/min) u Procainamide, 20 mg/min until u PVCs suppressed u 17 mg/kg given u Hypotension occurs u QRS widens by 50% or more u Then, infusion at mg/min

Tachycardia: Wide Complex (VT) Polymorphic (Torsades) u Treatment (limit to one antidysrhythmic) u Long QT (including Torsades w/o arrest) u Magnesium sulfate 10%, 1-2 g slow IV over 5 mins or greater u Lidocaine, mg/kg IV (max 3.0 mg/kg), mg/kg q 5 min to max 3 mg/kg u Other considerations u phenytoin, isoproterenol, or overdrive pacing

Interesting Questions What is a capture beat? What is a fusion beat? How do they help or hurt you in your ECG interpretation?