Ventricular asystole in the presence of a biventricular device.

In pacemaker-dependent patients with a newly implanted cardiac device, acute lead dislodgement constitutes one of the most common causes of loss of capture and ventricular asystole. In a biventricular system, it would be expected that such a potentially catastrophic event would be prevented with back-up right ventricular pacing unless both leads dislodge.