Appendix E Pacemakers Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Artificial Pacemaker A device used to provide artificial electrical stimulus to myocardial tissue to induce myocardial depolarization Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Components Power Source: battery unit called a pulse generator Conducting Wire: electrode that goes to the heart to provide the stimulus Return Wire: wire that returns to battery unit to complete the electrical circuit Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Chambers Paced Atrial Pacemaker Ventricular Pacemaker Sequential Pacemaker Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacing Response Triggered Inhibited Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Classification Chamber Paced Chamber Sensed Response Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Classification Single-Chamber Pacemakers Dual-Chamber Pacemakers Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Malfunction Failure to Capture Competition Runaway Pacemaker Battery Failure Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Placement Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Classification Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Paced Complexes Pacemakers often supplement, rather than supplant, the patient’s own rhythm. This rhythm strip shows a ventricular demand pacemaker that fires occasionally to supplement the patient’s underlying atrial fibrillation. Complexes C, D, E, and G are the patient’s normally conducted beats (note narrow QRS complexes). Complexes A, B, and F are initiated by the artificial ventricular pacemaker (note spikes preceding each wide QRS). Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Rhythms (Ventricular) A properly functioning pacemaker will show a sharp spike, followed immediately by depolarization of the chamber it is intended to pace. This rhythm strip shows ventricular pacemaker capturing every beat. Note absence of mappable P waves and sharp spikes followed immediately by wide QRS complexes. Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Rhythms (AV Synchronous) This rhythm strip shows an AV synchronous pacemaker capturing every beat. Note pacemaker spikes preceding both atrial and ventricular depolarization. Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Properly Functioning Ventricular Demand Pacemaker The pacemaker is set to fire whenever the patient’s intrinsic rate falls below 60 beats per minute. The first three complexes show the patient’s heart depolarizing at about 68 beats per minutes, so the pacemaker inhibited itself. It kicked in at the fourth complex when the rate dropped, and continued to pace at a rate of 60 beats per minute. Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Failure to Capture The underlying rhythm is atrial fibrillation, and the ventricular pacemaker is set at an unusually slow rate of 44 beats per minute. It fails to sense the patient’s own complexes and continues to fire regularly, regardless of underlying ventricular activity. When the pacemaker stimulus finds the ventricles refractory, it fails to capture. Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Competition This strip shows pacemaker spikes at a rate of 100 beats per minute, with an underlying ventricular tachycardia/fibrillation. The pacemaker is competing for control of the heart, but the irritable ventricular foci are winning. Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Sample Pacemaker Strips Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Fully Functional Atrial Pacemaker Showing 100% Capture Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Ventricular Pacemaker Showing 100% Capture (with Underlying Complete Heart Block) Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

AV Sequential (DVI) Pacemaker Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Properly Functioning Demand Pacemaker Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

DDD Pacemaker in AV Sequential Mode Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Sinus Rate Accelerates and Regains Control from Ventricular Demand Pacemaker Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Fails to Depolarize Consistently, Indicating Lead Fracture or Displacement Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Ventricular Pacemaker with 100% Capture Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Atrial Pacemaker with 100% Capture Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Non-capturing Pacemaker Competing with Supraventricular Rhythm in First Part of Strip, Converting to Ventricular Tachycardia Competing with Pacemaker at End of Strip Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Ventricular Demand Pacemaker Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ

Ventricular Pacemaker Showing 100% Capture Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ