Figure 1: Stored electrograms at the time of the syncopal
episode
Stored electrograms corresponding to the time of the patient’s syncopal
episode showing high frequency, non-physiologic (cycle length = 150
msec) noise on the ventricular (V) channel which saturates the
amplifier. The pacemaker interprets the noise as ventricular tachycardia
(VT) on the marker channel (M). There is pacing inhibition (no
ventricular pace [VP]) is noted). A = atrial channel, V =
ventricular channel, M = marker channel, VT = ventricular tachycardia,
AS = atrial sense, PVP = Post ventricular atrial refractory period
extension