Arrhythmogenic Cardiomyopathy Versus Viral Myocarditis in a Professional Athlete

Differentiating arrhythmogenic cardiomyopathy (ACM) from healed viral myocarditis in competitive athletes is challenging, particularly as advanced imaging increasingly detects myocardial abnormalities in asymptomatic individuals.

A 26-year-old professional football player was found to have lateral and inferior T-wave inversions during preseason screening. He was asymptomatic with normal biomarkers and excellent exercise capacity. Cardiac magnetic resonance demonstrated left ventricular enlargement with mildly reduced systolic function and 2 discrete regions of nonischemic replacement fibrosis without active inflammation. Ambulatory monitoring showed a very low ectopic burden without ventricular arrhythmias, and comprehensive cardiomyopathy genetic testing was negative. Multidisciplinary shared decision-making supported conditional clearance with ongoing surveillance and emergency preparedness.

This case highlights diagnostic uncertainty between ACM and postinflammatory scar, underscoring the necessity of contextual imaging interpretation and nuanced multimodal evaluation.

Distinguishing healed myocarditis from ACM in competitive athletes remains a significant diagnostic challenge, particularly when cardiac magnetic resonance demonstrates nonischemic myocardial fibrosis in otherwise asymptomatic individuals. Multimodality evaluation, longitudinal follow-up, and shared decision-making are essential to establish the correct diagnosis, guide risk stratification, and inform safe return-to-play decisions.