Automatically optimizing pacing output: An excellent idea, but with potentially lethal pitfalls

AutoCapture (AC) and Ventricular Capture Management (VCM) are pacing algori thms that attempt to automatically optimize pacing output, providing consis tent capture and enhancing device longevity. This report describes potentia lly serious consequences from use of these algorithms. In one pacemaker dep endent patient, AC malfunction led to failure of ventricular capture. This was fixed with a software correction. The potential seriousness of AC malfu nction leads to the recommendation that this software be downloaded into al l susceptible pacemakers. In a second patient, VCM malfunction resulted in unnecessary high output pacing. Our experience illustrates the need for pos tmarketing surveillance when embracing newer technology.