A 55-year-old patient was admitted to the emergency department with increasing dyspnea. He had a history of mitral and aortic valve replacement (mechanical valves) for rheumatic stenosis 10 years earlier. Over the past several months, he noticed swelling of the ankles, a dry cough, and dyspnea on light exercise such as walking. He was treated with anticoagulants, and 2 years earlier, amiodarone was started for paroxysmal atrial fibrillation. On admission, he was comfortable at rest but showed clear ankle swelling, diminished breath sounds suggesting pleural effusion, prominent jugular veins, and hepatomegaly. The blood pressure was 135/85 mmHg, and the heart rate was regular at 47/min. Valve sounds were normal. An electrocardiogram (ECG) showed a slow sinus rhythm and left bundle branch block. A chest X-ray revealed a slightly enlarged heart and bilateral pleural effusion.