Enhanced efficacy of oral sotalol for sustained ventricular tachycardia refractory to type I antiarrhythmic drugs.
Sotalol is a nonselective beta-adrenergic blocking agent with Vaughn-Williams class III activity. Its efficacy was tested in 9 patients with sustained ventricular tachycardia (VT) that had previously remained inducible during electrophysiologic testing of type I drugs (procainamide or quinidine). Eight patients had coronary artery disease with remote myocardial infarction and 1 had cardiomyopathy (ejection fraction 0.34 +/- 0.08, mean +/- standard deviation). Type I drugs prolonged the effective refractory period of the right ventricle 12 +/- 14% and prolonged the VT cycle length 41 +/- 24%. In contrast, despite an equivalent effect on the effective refractory period, a sustained VT could no longer be initiated in any of the 8 patients ultimately tested while taking oral sotalol. Daily doses averaged 600 +/- 103 mg and blood levels associated with VT suppression in electrophysiologic studies were generally greater than 3,000 ng/ml. In addition, sotalol was moderately effective at reducing ventricular ectopic activity measured by ambulatory electrocardiography. Over a mean follow-up of 23 months (range 1 to 37), mild heart failure (3 patients), symptomatic brady-cardia requiring pacemaker (1) and drug-related polymorphous VT (1) have occurred. Sudden death occurred in 1 patient and nonfatal VT recurrence was noted in 2. Five of 8 chronically treated patients currently are successfully treated with minimal side effects. Sotalol appears to be a promising antiarrhythmic drug in the treatment of serious ventricular arrhythmias, even in patients refractory to type I antiarrhythmic agents.
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D002304:Cardiac Pacing, Artificial; D002986:Clinical Trials as Topic; D004341:Drug Evaluation; D004562:Electrocardiography / Q000379:methods; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011342:Procainamide / Q000627:therapeutic use; D011802:Quinidine / Q000627:therapeutic use; D011897:Random Allocation; D013015:Sotalol / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use; D013610:Tachycardia / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology / Q000517:prevention & control*
D000889:Anti-Arrhythmia Agents; D013015:Sotalol; D011802:Quinidine; D011342:Procainamide