Procainamide-induced lupus erythematosus pericarditis encountered during coronary bypass surgery

Abstract Procainamide is probably the most common offending drug responsible for the drug-induced lupus erythematosus syndrome today. Pericarditis has been reported to occur in from 14 to 18 per cent of the cases of procainamide-induced lupus erythematosus, and occasional reports of massive pericardial effusion, pericardial tamponade and constrictive pericarditis have appeared in the literature. We describe a patient who presented with features of procainamide induced lupus erythematosus without any clinical evidence of pericarditis. He underwent coronary bypass surgery 12 days after administration of the drug was stopped and was found to have a significant pericardial effusion at the time of surgery; histologic examination of pericardial tissue and pericardial fluid confirmed that the pericardial effusion was related to the procainamide-induced lupus syndrome. The incidence of pericarditis in procainamideinduced lupus erythematosus may be higher than presently accepted figures would indicate. Symptoms and signs related to procainamide-induced lupus pericarditis may cause diagnostic confusion with common postoperative bypass complications; the full implications of this disease entity to the patient undergoing coronary bypass are unknown.