New-Onset Dyspnea and Right Heart Failure

tient’s hypoxemia worsened and he was transferred to the intensive care unit. A pulmonary artery catheter was inserted which revealed a pulmonary artery pressure of 64/24 mm Hg, a pulmonary capillary wedge pressure of 8 mm Hg, and a cardiac index of 3.7 l/min/m 2 . What is your diagnosis? A 65-year-old male was admitted to hospital with nausea, vomiting and dehydration. He had been diagnosed 6 months earlier with adenocarcinoma of the prostate (Gleason grade 3 + 4) and had completed a course of pelvic radiation 6 weeks prior to admission. He also had a history of rheumatoid arthritis treated with methotrexate, which had been stopped 2 weeks prior to admission due to pancytopenia and elevated liver enzymes. Upon examination, his vital signs were normal and his physical exam was unremarkable. His laboratory data on admission revealed a hemoglobin of 11.2 g/dl and a platelet count of 90,000. Serum electrolyes, glucose, blood urea nitrogen and creatinine were normal. The electrocardiogram was normal and a chest X-ray was unremarkable. During his admission, his hematocrit and platelet continued to drop and he was noted to have evidence of hemolysis on his peripheral blood smear with an elevated serum LDH of 12,000 U/l. A presumptive diagnosis of thrombotic thrombocytopenic purpura was made and plasmapheresis was started. After 2 days of plasmapheresis, the platelet count had stabilized; however, the patient began to complain of dyspnea and his oxygen saturation was noted to be 85% on room air. A CT angiogram of the chest (see fig. 1 ) was performed and was negative for pulmonary embolism. An echocardiogram revealed right ventricular enlargement with decreased right ventricular systolic function with an estimated right ventricular systolic pressure of 74 mm Hg. Two months earlier, the patient had an echocardiogram that was normal. The paReceived: August 3, 2013 Accepted after revision: August 23, 2013 Published online: December 11, 2013