Prediction of successful suppression of sustained ventricular tachyarrhythmias by serial drug testing from data derived at the initial electrophysiologic study

This study investigated whether data available after the initial electrophysiologic study in patients with sustained ventricular tachyarrhythmia could identify those patients in whom serial drug testing is likely to be efficacious. One hundred six patients with inducible sustained ventricular tachyarrhythmia, whose initial study included short-term drug testing with intravenous procainamide, were evaluated. The baseline arrhythmia induced (in the absence of all antiarrhythmic drugs) was monomorphic tachycardia with a cycle length >200 ms in 81 patients and ventricular flutter or fibrillation in the remaining 25 patients. After intravenous infusion of procainamide (1,250 ± 300 mg), a ventricular tachyarrhythmia could still be induced in 80 patients during testing with up to three extrastimuli. Serial drug testing with one to four trials of oral conventional and investigational agents was then undertaken.