Midventricular Hypertrophic Cardiomyopathy With Apical Aneurysm Presenting as Persistent ST-Segment Elevation Mimicking Acute Myocardial Infarction

BACKGROUND: ST-segment elevation on electrocardiography is classically associated with acute transmural myocardial ischemia due to coronary artery occlusion and is central to the diagnosis of ST-segment elevation myocardial infarction. However, persistent ST-segment elevation may also reflect nonischemic structural heart disease. CASE SUMMARY: A 62-year-old woman presented with chest pain and widespread ST-segment elevation with T-wave inversion. Coronary angiography showed no obstructive disease. Echocardiography and cardiac magnetic resonance revealed midventricular hypertrophic cardiomyopathy with systolic midcavity obstruction and a left ventricular apical aneurysm. Nonsustained ventricular tachycardia was documented, and an implantable cardioverter-defibrillator was placed for primary prevention. DISCUSSION: This case illustrates a rare, high-risk hypertrophic cardiomyopathy phenotype in which persistent ST-segment elevation mimics acute myocardial infarction. TAKE-HOME MESSAGES: Midventricular hypertrophic cardiomyopathy with apical aneurysm can present with persistent ST-segment elevation and T-wave inversion, mimicking myocardial infarction. Electrocardiography is a valuable diagnostic and surveillance tool in this phenotype, as characteristic ST-segment abnormalities may precede or complement imaging findings.