A 74-year-old man was referred to hospital for sustained dyspnea. The patient was normotensive (110/70 mmHg) with clinical evidence of congestive heart failure. ECG showed atrial flutter (145 bpm). Transthoracic echocardiography demonstrated a mildly dilated left ventricle with severe systolic dysfunction and a big irregular mobile mass, a mildly dilated right ventricle with moderate systolic dysfunction and a large mass protruding into the cavity. The patient was treated surgically for high embolic and sudden death risk after coronarography, which showed a single stenosis (70%) of the left anterior descending coronary. Myocardial biopsy demonstrated interstitial and endocardial fibrosis, no inflammatory pattern. After 6 months of follow-up echocardiography was normal.