Pacemaker-Mediated Arrhythmias

Pacemaker-mediated arrhythmia (PMA) is a broad term used to describe the abnormal rhythms in which the pacing system contributes importantly to. There are a variety of arrhythmias caused by or related to a pacing system. But in this chapter, we focus on only those arrhythmias mediated by a dual (atrial and ventricular) pacing system in patients with intact retrograde VA conduction. We have re-classified these arrhythmias into three types: (1) repetitive reentrant ventriculoatrial synchrony (RRVAS), (2) repetitive non-reentrant ventriculoatrial synchrony (RNRVAS), and (3) repetitive non-reentrant ventriculoatrial 1:2 synchrony (RNRVA1:2S). Although these three types of pacemaker-mediated arrhythmias share a common feature in that there is retrograde VA conduction, their clinical manifestations, mechanisms, and pacemaker programming features are distinctively different. In this chapter, we have discussed each of these arrhythmias using clinical cases, ECG tracings, and schematic diagrams.