On presentation, the patient was in moderate respiratory distress and was significantly volume overloaded (ie, 3+ lower extremity edema and rales in more than two thirds of lung fields bilaterally). A laboratory examination was remarkable for severe microcytic anemia (hemoglobin concentration, 6.4 g/dL), a WBC count of 24.1 × 103 cells/μL with a leftward shift, an international normalized ratio of 2.77, a BUN concentration of 46 mg/dL, and a creatinine concentration of 1.5 mg/dL. Blood cultures were drawn and remained sterile. An ECG showed atrial fibrillation with controlled ventricular response (heart rate, 88 beats/min), right axis deviation, left posterior hemi-block, and nonspecific ST-T changes. Chest radiograph findings were consistent with pulmonary vascular congestion, without the presence of discrete infiltrates. The cardiac silhouette showed evidence of dilated pulmonary arteries. Echocardiography demonstrated a normal functioning mechanical mitral valve and a bioprosthetic tricuspid valve, with no paravalvular or intravalvular regurgitation. Left ventricular systolic function was normal. There was biatrial enlargement with mild right ventricular dilatation and dysfunction. Right ventricular systolic pressures could not be obtained secondary to the absence of tricuspid regurgitation. A bleeding gastric arteriovenous malformation was cauterized, and the anemia was corrected. Multiple attempts at diuresis were unsuccessful, as they were limited by worsening renal function.