Occurrence and significance of arrhythmias associated with atrial-triggered ventricular pacing.

A review of electrocardiograms from 85 patients with atrial-triggered ventricular pacing (VAT, VDD, DDD) showed that various disturbances of rhythm were relatively common, and that the effects of an arrhythmia could be aggravated by this type of pacing. In certain circumstances even potentially dangerous ventricular extrasystoles were induced by the pacemaker. Abnormal triggering, sometimes with regular sinus rhythm, could also induce tachycardia. Our observations provided indications for a pacemaker design that would avoid such disturbing effects. The best available pacer for atrial-triggered ventricular pacing is the programmable DDD type.