Case Background

Our patient is a 45-year-old man with a chief complaint of progressive shortness of breath and ankle swelling of six months duration.

The pertinent features of his history include the following: about two years ago he noted the nearly simultaneous onset of dyspnea on exertion and peripheral edema. He sought medical attention and was told that his X ray revealed an enlarged heart and that his electrocardiogram was abnormal.

He improved with therapy including salt restriction, digitalis, diuretics and an angiotensin converting enzyme inhibitor (ACE-I). He never fully returned to normal activity and continued to have residual fatigue and dyspnea with physical exertion. Three months ago he began having orthopnea and paroxysmal nocturnal dyspnea.

There is no history of chest pain, hypertension, heart murmur, rheumatic fever or pulmonary edema. There are no known significant contributing risk factors for heart disease. Other than his male sex, he has no risk factors for coronary artery disease. There is no family history of heart disease and no history of alcohol or drug abuse. He also denies any risk factors for HIV exposure, recent travel abroad or significant emotional stress.

Choose the best diagnosis based on the history in our patient: