Pericardial tamponade. A presenting manifestation of procainamide-induced lupus erythematosus.

Procainamide, a frequently sued antiarrhythmic agent, may produce a syndrome clinically indistinguishable from idiopathic lupus erythematosis. Pericarditis with or without effusion is occasionally a prominent manifestation of the disease, but cardiac tamponade is exceptional. The patient described had a clinically evident and laboratory confirmed drug-induced syndrome complicated by an unusually severe pericarditis with effusion and tamponade necessitating pericardiocentesis. Treatment with prednisone produced impressive amelioration of the pericarditis with no recurrence of the lupus erythematosis syndrome during a prolonged period of observation following cessation of corticosteroid therapy. Prompt initation of steroid treatment in drug-induced lupus erythematosus complicated by massive pericardial effusion is strongly suggested by this experience.