A 38-year-old man was admitted to the cardiology emergency department for palpitations. He had been diagnosed 3 years earlier with hypertrophic cardiomyopathy and was receiving chronic treatment with beta-blockers and low-dose aspirin. Physical examination was unremarkable. Electrocardiogram showed right bundle branch block associated with diffuse abnormal ST-segment changes ( Fig. 1 ). Troponin I was increased slightly, at 0.11 ng/mL (normal < 0.05). Transthoracic echocardiographic examination revealed concentric left ventricular hypertrophy with maximal midventricular thickening without significant left ventricular obstruction and a large apical aneurysm ( Video 1 ). Coronary angiography was normal. The left ventricular cine-angiogram showed midcavitary obliteration at end-systole and a large aneurysm ( Video 2 ). Late gadolinium enhancement cardiac magnetic resonance imaging found transmural fibrosis of the apex and confirmed maximal left ventricular wall thickening at the midventricular level ( Video 3 , Fig. 2 ). Exercise testing did not produce arrhythmias. Treatment with a vitamin K antagonist was initiated.
