Procaine is effective for minimizing postischemic ventricular fibrillation in cardiac surgery

Procaine hydrochloride was added to cardioplegia and studied for its efficacy in stabilizing the postischemic rhythm after aortic declamping in cardiac surgery. Fifty-six patients scheduled for coronary artery bypass grafting (CABG), were included in a randomized, double-blind study. The patients were anesthetized with isoflurane, low-dose fentanyl, diazepam, and pancuronium. In the study group (28 patients), St. Thomas' Hospital cardioplegic solution II (Plegisol) was prepared with 1 mM procaine. The control group (28 patients) was given the same cardioplegia with saline. Ventricular fibrillation (VF) occurring after declamping was treated with direct current (DC) shock (8-12-12-20 J). There were no significant differences with regard to demographic properties or anesthesiologic and surgical treatment. Two patients (7%) in the procaine group required DC shock for VF, compared to 28 (100%) in the control group (P < 0.001). The amount of lidocaine (mean +/- SEM) given for resistant dysrhythmias was 3.6 mg +/- 3.6 in the procaine group compared to 35.7 mg +/- 9.2 in the control group (P < 0.002). One patient in each group required temporary pacing. The number of synchronized DC shocks for conversion of atrial fibrillation was lower in the procaine group (P < 0.05). The enzyme release the first day after surgery was lower in the procaine group (P < 0.05). Procaine (1 mM) in cardioplegia stabilizes the postischemic rhythm in CABG surgery in humans without any observed adverse effects.