Uremic pericarditis as a cause of cardiac tamponade.

Uremic pericarditis may complicate either acute or, more commonly, chronic renal failure. When dialysis is not employed, uremic pericarditis is usually a preterminal event and is characterized by a serofibrinous exudation of an amount inadequate to cause cardiac tamponade. Nevertheless, cardiac tamponade may uncommonly be observed in nondialyzed patients. Cardiac tamponade, which may be life-threatening, is more common in dialyzed than in nondialyzed patients with chronic renal failure. The primary causes of cardiac tamponade in uremic pericarditis in order of decreasing frequency are (1) pericardial effusion, usually of the serosanguineous type, (2) massive hemorrhage into the pericardial sac and (3) collagenization of pericardial exudate. From pathologic evidence, the following forms of therapy appear appropriate to manage uremic pericarditis that has reached the stage of causing cardiac tamponade. For effusion, pericardiocentesis or parietal pericardiectomy are logical procedures. Massive hemorrhage into the pericardial sac is usually attended by clotting and requires pericardiotomy and evacuation of clot. Collagenization of exudate yields an encasing, fibrous shell over the heart and requires decortication, as is practised in classical constrictive pericarditis.