Nonuniform recovery of excitability in the left ventricle.

The purpose of this study was to determine left ventricular activation, dispersion of refractoriness, and total recovery time in patients with coronary artery disease and ventricular tachycardia and in patients with the long QT syndrome and to compare these patients with a group of normal patients. Left ventricular endocardial catheter mapping and left ventricular refractory period determination were performed in 18 patients. Group 1 consisted of seven patients with no heart disease and no arrhythmia; group 2 consisted of six patients with previous infarction and sustained ventricular tachycardia; and group 3 consisted of five patients with prolonged QT interval and previous cardiac arrest. Total left ventricular endocardial activation was significantly longer in group 2 (75 +/- 23 msec, mean +/- SD) compared with group 1 (34 +/- 9 msec, p less than 0.01) and group 3 (42 +/- 5 msec, p less than 0.05). Dispersion of refractoriness was significantly greater in group 3 (87 +/- 27 msec) than in group 1 (40 +/- 14 msec, p less than 0.01) and group 2 (53 +/- 14 msec, p less than 0.05). Dispersion of total recovery time was significantly greater in group 2 (90 +/- 30 msec) than in group 1 (52 +/- 14 msec, p less than 0.05) as well as group 3 (114 +/- 43 msec) compared with group 1 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)