A 57-year-old man was admitted to the hospital for evaluation of dyspnea, orthopnea, cough, and paroxysmal nocturnal dyspnea of four days' duration. Chronic renal failure secondary to Balkan nephropathy had necessitated long-term hemodialysis during the last two years. On admission, the BP was 141/94 mm Hg, with a paradoxical pulse of 20 mm Hg and a pulse of 95 beats per minute. With the patient's head elevated 30° above horizontal, jugular venous distention was noted to the angle of the jaw. The carotid arterial pulse was diminished in amplitude. Lung examination disclosed diffuse scattered inspiratory and expiratory wheezing with left subscapular dullness to percussion (Ewart's sign). There was a diffuse area of precordial dullness; the apical impulse was not palpable. S1 and S2 were diminished in intensity and no other heart sounds were noted. An ECG disclosed diminished QRS voltage, electrical alternans, and nonspecific repolarization changes, and a