The antiarrhythmic effects of d-sotalol.

The antiarrhythmic properties of d-sotalol were studied in 38 patients undergoing electrophysiologic studies. Programmed electrical stimulation studies were performed in 28 men and in 10 women with a mean age of 67 years and a mean ejection fraction of 37 +/- 3%. All patients had inducible ventricular tachycardia while they were off all antiarrhythmic therapy. D-sotalol was given as a 2 mg/kg infusion over 15 minutes and did not significantly change the PR, QRS, or QTc intervals from baseline values in the group as a whole. In the group protected by d-sotalol, the percent change in the QTc interval as well as the percent change in refractoriness was significantly increased as compared to the group not protected. D-sotalol also significantly decreased heart rate. D-sotalol prevented the induction of ventricular tachycardia in 18 of the 38 patients, while significantly slowing the rate of the ventricular tachycardia in the group that could still have tachycardia provoked. Seventeen patients were tested on procainamide and only four were protected, while d-sotalol prevented the induction of ventricular tachycardia in 7 of these 17. Eleven patients were discharged on oral d-sotalol doses ranging from 100 to 400 mg twice daily. One patient died 1 month post discharge due to an acute myocardial infarction, and one patient had a cardiac arrest while on d-sotalol and survived and was switched to amiodarone therapy. The remaining nine patients are alive and well at 14 +/- 3 months. D-sotalol appears to be an effective antiarrhythmic drugs and appears to be well tolerated.