Reproducibility of ventricular tachycardia suppression by antiarrhythmic drug therapy during serial electrophysiologic testing in coronary artery disease.

The short-term reproducibility of pharmacologic suppression of ventricular tachycardia (VT) induced by programmed cardiac stimulation was tested in patients with coronary artery disease presenting with documented recurrent VT or ventricular fibrillation. Sixty-three consecutive patients in whom sustained VT (30 patients) or nonsustained VT (33 patients) was induced by programmed cardiac stimulation without antiarrhythmic drug treatment, and in whom at least 1 oral antiarrhythmic drug regimen suppressed the induced VT during serial electrophysiologic testing, were entered into the study. Programmed cardiac stimulation was repeated after a mean of 37 +/- 14 hours during the same antiarrhythmic drug regimen. No VT was induced in 59 of the 63 patients during the second study, resulting in a rate of 94% for short-term reproducibility of pharmacologic suppression of induced VT. Of the remaining 4 patients, programmed cardiac stimulation during the second drug study induced sustained VT in 1 patient and nonsustained VT in 3 patients. There was no significant difference in mean right ventricular effective refractory period and QT interval between the first and second drug study. Thus, in this selected population of patients, pharmacologic suppression of electrically induced VT is a reproducible phenomenon.