Myocardial protection by lidocaine hydrochloride in aorto-coronary bypass surgery.

Myocardial protective effect of lidocaine hydrochloride on the ischemic myocardium was evaluated by serum (MB-CK) and cardiac function in 48 patients; 24 patients in control (C) and 24 patients in lidocaine-treated group (L), who underwent aorto-coronary bypass surgery. Lidocaine hydrochloride, 1 mg/min was administered by continuous drip infusion from initiation of anesthesia, and throughout the operation and postoperative period for 24 hours. There were no significant differences between two groups with regard to duration of cardioplegia and cardiopulmonary bypass, hypothermic level and the number of grafts implanted. Serum MB-CK at 18-24 hours following cardioplegia was 39.5 +/- 15.2 I.U. (C) and 14.2 +/- 4.0 I.U. (L), (p less than 0.05). Cardiac index and stroke volume index were significantly increased in the lidocaine-treated group at 24 hours following aorto-coronary bypass surgery, as compared to the control group. Lidocaine thus appears to be beneficial in aorto-coronary bypass surgery to prevent ischemic changes in the myocardium.