Prevention of recurrent life-threatening ventricular arrhythmias by temporary cardiac pacing.

Overdrive pacing has been applied in 26 patients to prevent frequent recurrent ventricular fibrillation (VF) and ventricular tachycardia (VT) occurring in the setting of ventricular extrasystole of 2-5 degrees graded by Lown. These patients had 3-47 recurrent attacks of VF and VT (11.4 +/- 2.4) which were not prevented with antiarrhythmic agents. Overdrive pacing was continued for 2-236 hours (21.3 +/- 3.7) and appeared to be effective in 23 (88.4%) of the 26 patients including those with prolonged QT intervals. Atrial pacing was more effective than ventricular overdriving and required stimulation at a slower rate. Antiarrhythmic therapy and overdrive pacing in combination were more effective than both used independently. Suppression of ventricular extrasystole and prevention of life-threatening arrhythmias were achieved by increasing the heart rate by 23.2 +/- 4.5 beats/min.