Life-threatening ventricular dysrhythmias with inadvertent asynchronous temporary pacing after cardiac surgery

POTENTIALLY lethal arrhythmias have long been recognized as a rare complication of cardiac pacing. The incidence of this catastrophic event is thought to be low even in cases of asynchronous ventricular pacing, presumably because the electrical stimuli provided by the pulse stimulator usually remain below the fibrillation threshold. Furthermore, the possibility of serious pacemaker-induced arrhythmias has been greatly reduced by the introduction of advanced demand modes of pacing into clinical practice. Nevertheless, this problem can still be encountered when pacemaker pulse generator is switched to asynchronous mode. We report a case in which a recently introduced and commonly used epicardial temporary pacemaker (Model 5388, Medtronic Inc., Minneapolis, MN) was accidentally switched several times to asynchronous mode, causing ventricular fibrillation in a patient after cardiac surgery.