Effectiveness of Procaine Amide in Digitalis-Induced Ventricular Tachycardia.

Abstract

Rapid, intraven. admn. of procaine amide (Pronestyl) (10-20 mg./kg.) was effective in reverting ventricular tachycardia to normal sinus rhythm when the tachycardia was produced acutely in anesthetized dogs by large intraven. doses of cardiac glycosides. In most instances the reversion was temporary and additional procaine amide was necessary to maintain the normal rhythm. Such additional injns., when repeated several times, did not produce ecg. signs of cumulative toxicity. Slow idioventricular rhythms or cardiac arrest following procaine amide admn. in 6 of the 14 expts. demonstrated that complete a-v heart block may be masked by the ventricular tachycardia. Abolition of the latter arrhythmia may result in ventricular arrest. Procaine amide failed to increase the lethal dose of ouabain as detd. by limited "cat-unit" studies.