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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