Runaway pacemaker. A case report with a runaway rate of 2100 ppm.

A case of runaway pulse generator is described. A Vitalith C-23 developed runaway on the 13th postoperative day, without any preceding changes in the rate or amplitude of the pulse generator spike. The rate of runaway was 2100 pulses per minute (ppm), one of the highest rates ever reported. The ventricle was not captured by the runaway pulse generator, but was paced effectively by a temporary demand pacemaker (Medtronic 5880A) which was left in case of displacement of the implanted pacing lead. The reasons why the temporary pacemaker was not inhibited are discussed.