Characteristics of ventricular ectopic beats in patients with ventricular tachycardia. A 24-hour Holter monitor study.

A total of 99 consecutive 24-hour Holter recordings with ventricular tachycardia were reviewed. Ventricular premature beats which occurred alone, and ventricular premature beats which initiated ventricular tachycardia were examined to determine which characteristics correlated with occurrence of ventricular tachycardia and which predicted rate and duration of ventricular tachycardia. The preceding R-R interval, the coupling interval, and a ratio of the two were examined. We found that ventricular tachycardia rate and duration increase with a shorter coupling interval, and the coupling interval/preceding R-R ratio was significantly different in single beats not initiating ventricular tachycardia. The ratio for the beat initiating ventricular tachycardia was smaller, indicating more prematurity.