In other words, instead of terminating it, the pacing actually perpetuated and worsened the initial condition in about 20 percent of the cases. That percentage approximates the frequency with which this is thought to occur in patients with implanted defibrillators. |
In the beginning, there is a single rotating wave -- the 'culture dish' analog of ventricular tachycardia. After a short period, we applied trains of pulses in an attempt to terminate this wave. |
Ventricular tachycardia and fibrillation are the leading causes of sudden death in the developed world. Yet, in humans and animals the anatomy is so complex that mechanisms of such arrhythmias are difficult to dissect systematically. |