Tension hydrothorax is a rare complication of pneumonectomy for pleural mesothelioma and an exceptionally rare cause of heart failure. We describe a patient who had undergone extrapleural pneumonectomy, chemotherapy, and radiation for pleural mesothelioma and who developed heart failure symptoms within months of the completion of treatment. Investigation showed a massive left pleural effusion resulting in tension hydrothorax, mediastinal shift, and evidence of right heart failure with constrictive physiology and low cardiac output. Therapeutic thoracentesis resulted in increase in cardiac output and symptomatic improvement.
