Pacemaker‐mediated arrhythmias

Abstract

Pacemakers can be directly involved in initiating or sustaining different forms of arrhythmia. These can cause symptoms such as dyspnea, palpitations, and decompensated heart failure. Early detection of these arrhythmias and optimal pacemaker programming is pivotal. The aim of this review article is to summarize the different types of pacemaker‐mediated arrhythmias, their predisposing factors, and mechanisms of prevention or termination.

Treatment of atypical pacemaker‐mediated tachycardia with ablation of the retrograde atrioventricular nodal pathway

“…Programming should also minimize events that desynchronize the atrium and ventricle 1,2 . Setting atrial sensitivity to a value that senses sinus atrial EGMs but not retrograde EGMs is rarely practical 1,2 . In our case, programming to the VVIR mode would have compromised AV synchrony and forced unnecessary ventricular pacing; the PVARP could not be extended to prevent VA conduction without symptomatic limitation of tracking sinus tachycardia; PMT occurred with an unusually short SAV; the onset of PMT did not require desynchronizing events; and the amplitudes of the sinus and retrograde atrial EGMs were comparable (Figure 2).…”

“…Endless loop, AV reentry is the most common form of PMT 2 . The pacemaker provides the anterograde limb and cardiac conduction provides the retrograde limb.…”

“…The primary programming options to prevent PMT include setting (a) a nontracking mode, (b) the PVARP longer than the conducted VA interval, and (c) a short SAV to prevent retrograde conduction 1,2 . Programming should also minimize events that desynchronize the atrium and ventricle 1,2 . Setting atrial sensitivity to a value that senses sinus atrial EGMs but not retrograde EGMs is rarely practical 1,2 .…”

“…In our case, programming to the VVIR mode would have compromised AV synchrony and forced unnecessary ventricular pacing; the PVARP could not be extended to prevent VA conduction without symptomatic limitation of tracking sinus tachycardia; PMT occurred with an unusually short SAV; the onset of PMT did not require desynchronizing events; and the amplitudes of the sinus and retrograde atrial EGMs were comparable (Figure 2). In addition, pacemakers have various algorithms that interrupt PMT, 1,2 but these are of limited value if PMT is repetitive.…”

Pacemaker‐mediated tachycardia in a dual‐lead CRT‐D: What is the mechanism?

“…PMTs are a known and common complication of cardiac device implant 4–6 . They involve the device repeatedly tracking a retrograde impulse from a previous paced beat.…”