Runaway: arrhythmia, carelessness or an obsolete phe­nomenon7

pp 291-293

Abstract

Runaway is an uncommon pacemaker malfunction, character­ized by fast and erratic spikes at non-physiological rates. This potentially lethal, low or depleted battery related failure, can be easily avoided by means of an adequate periodic follow-up. Two patients with complete (third degree) atrioventricular block, outfitted with eight year old single-chamber pacemak­ers (Medtronic Minix ST 8330 and CPI Triumph VR 1124) were admitted because of pre-syncopal episodes. The ECGs showed typical "runaway" phenomena: high rate (2000 bpm) non-capturing spikes alternating with pacing at 60 bpm. During pulse generator replacement, both implanted leads showed normal parameters.