普魯卡因胺 Procainamide HCl

作用機轉

A class 1A antiarrhythmic agent, procainamide exhibits cardiac action similar to that of quinidine. It is considered both a supraventricular and ventricular antidysrhythmic. Procainamide prolongs the refractory times in both the atria and ventricles, decreases myocardial excitability, and depresses automaticity and conduction velocity. It has anticholinergic properties that may contribute to its effects. Procainamide’s effects on heart rate are unpredictable, but it usually causes only slight increases or no change. It may exhibit negative inotropic actions on the heart, although cardiac outputs are generally not affected. On ECG, QRS widening, and prolonged PR and QT intervals can be seen. The QRS complex and T wave may occasionally show some slight decreases in voltage.