Correlation between signal-averaged electrocardiogram and programmed stimulation in patients with and without spontaneous ventricular tachyarrhythmias.

This study examined the incidence of delayed ventricular activation on signal-averaged electrocardiograms and the incidence of inducible sustained ventricular tachycardia (VT) at programmed stimulation (1 or 2 extrastimuli) in patients with and patients without spontaneous ventricular tachyarrhythmias. The correlation between delayed ventricular activation and inducible VT was investigated in 371 patients with acute myocardial infarction (AMI). In 32 patients with no ventricular disease and no spontaneous arrhythmias (group I), ventricular activation time averaged 115 +/- 2 ms, compared with 166 +/- 3 ms (p less than 0.001) for 65 patients with spontaneous ventricular tachyarrhythmias late after AMI (group II). In AMI patients with no spontaneous arrhythmias, ventricular activation time averaged 133 +/- 2 ms for 306 patients studied 1 to 4 weeks after AMI (group III) and 130 +/- 2 ms for 67 patients studied 3 to 12 months after AMI (group IV). The values for group III and group IV patients were each significantly higher than for group I (p less than 0.001), but lower than that for group II (p less than 0.001). The incidence of delayed ventricular activation was 89% for group II, 26% for group III and 18% for group IV. Sustained VT was not inducible in group I patients, but was inducible in 78% of group II (p less than 0.001 vs group I) and 20% of group III (p less than 0.05 vs group I; p less than 0.001 vs group II) (group IV was not studied).(ABSTRACT TRUNCATED AT 250 WORDS)