ABSTRACT
Because supraventricular tachyarrhythmias after open heart surgery are often resistant to DC cardioversion and treatment with antiarrhythmic agents, we sometimes have difficulty in the postoperative management of these arrhythmias. We attempted to use intravenous infusion of diltiazem hydrochloride (3-5mcg/kg/min) for 6 patients with supraventricular tachyarrhythmias, 5 of whom had atrial fibrillation and 1 with sinus tachycardia after open heart surgery. The ventricular rate was remarkably reduced from the pretreatment value by this infusion therapy. Diltiazem infusion during atrial fibrillation in 5 patients regularized the ventricular rate (normalization of R-R intervals). These results indicate that diltiazem was effective in obtaining almost constant preload with each cardiac cycle for the postoperative deteriorated cardiac muscle. The hemodynamic parameters obtained with the Swan-Ganz catheter showed that both right and left ventricular functions improved after the infusion of diltiazem. There was no adverse effect due to the administration of diltiazem. We concluded that the intravenous infusion of diltiazem is an effective method to manage supraventricular tachyarrhythmias after open heart sugery without deterioration of the cardiac function or side effects.