Isolated Cardiac Rhabdomyoma With Marked ST-Segment Elevation: Benign Tumor, Malignant ECG

Cardiac rhabdomyoma is the most common primary cardiac tumor in infancy and is frequently associated with tuberous sclerosis complex (TSC).

A 5-month-old asymptomatic infant presented with electrocardiography (ECG) showing marked ST-segment elevation in the anterolateral and inferior leads. Echocardiogram showed a cardiac rhabdomyoma in the left ventricle with preserved ventricular function and no evidence of hemodynamic compromise. Cardiac biomarkers were negative. There was no other evidence, clinically or radiologically, for TSC. Genetic testing for TSC was also negative. The infant remained clinically well with persistent but stable ECG changes at 10-month follow-up.

This case highlights a rare but striking ECG presentation of a benign cardiac tumor, emphasizing the importance of clinical context when interpreting ischemic-appearing ECG changes in infants.

Cardiac rhabdomyomas may present with marked ST-segment elevation on ECG, even in the absence of symptoms or myocardial injury. Ischemic-appearing ECG changes in infants with cardiac tumors may follow a benign clinical course and warrant careful longitudinal assessment rather than immediate intervention.