Usefulness of sotalol for drug-refractory malignant ventricular arrhythmias

Fifty patients with recurrent sustained symptomatic ventricular tachycardia (43 patients) or ventricular fibrillation (7 patients) resistant to a mean of 2.8 + 1.4 antiarrhythmic drugs were treated with Sotalol, a beta-adrenergic receptor antagonist, and 45 underwent invasive electrophysiologic testing before and after sotalol therapy. The arrhythmia became noninducible in 10, was slower and hemodynami-cally well tolerated in 12 and was poorly tolerated in 23. Four patients were empirically treated with long-term administration of oral sotalol as were 21 patients who either had noninducible arrhythmia (10 patients) or had hemody-namically stable ventricular tachycardia (11 patients).In these 25 patients treated with long-term administration of sotalol, there was no recurrence of ventricular tachycardia in the group with noninducible arrhythmia, whereas 37% of patients with inducible ventricular tachycardia had new ventricular tachycardia or sudden death. Programmed ventricular stimulation with up to three ex-trastimuli proved to be an excellent predictor of drug efficacy and a good predictor of inefficacy. A positive prior response to amiodarone was not a reliable indicator of a positive response to sotalol.Side effects included those attributed to both beta-adrenergic blockade as well as proarrhythmic effects. The latter were observed in two of four patients with a QT interval >600 ms. Sotalol was found to be effective therapy for a subset of patients with ventricular tachycardia unresponsive to type IA drugs