Verapamil in ventricular tachycardia.
We compared the effects of verapamil to high dose procainamide on the rate of inducible and spontaneously occurring ventricular tachycardia (VT) in 10 patients. Verapamil induced a significant increase in the rate of tachycardia (R-R interval decreased from 278 +/- 54 to 233 +/- 32 ms, mean +/- SD; p less than 0.025 by paired t test) while procainamide slowed the tachycardia (mean R-R interval was 328 +/- 72 ms, p less than 0.02). Verapamil prevented the induction of sustained VT and was effective as chronic oral antiarrhythmic therapy in 2 patients. The accelerated VT culminated in ventricular fibrillation in 1 patient. It is assumed that verapamil may have either increased conduction velocity or shortened the reentrant cycle. This may be related either to a primary effect of the drug or secondary to increased catecholamine stimulation due to a vasodilatory effect.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002304:Cardiac Pacing, Artificial; D003327:Coronary Disease / Q000150:complications; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D005260:Female; D006322:Heart Aneurysm / Q000150:complications; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications; D009205:Myocarditis / Q000150:complications; D011342:Procainamide / Q000627:therapeutic use; D013610:Tachycardia / Q000188:drug therapy*; D014700:Verapamil / Q000009:adverse effects / Q000627:therapeutic use*
D014700:Verapamil; D011342:Procainamide