Borderline Arrhythmogenic Cardiomyopathy in an Athlete

BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) bears a considerable risk of malignant arrhythmias and heart failure, but diagnosis in athletes can be challenging. CASE SUMMARY: We present a male 52-year-old long-distance runner with palpitations, a dilated right ventricle with apical akinesia, nonsustained ventricular tachycardia, and negative genetic testing. We performed combined stress echocardiography and cardiopulmonary exercise testing showing blunted exercise response and a decrease in right ventricular strain during exercise. Although the modified task force criteria were not met, a diagnosis of ACM based on impaired exercise response was made, and termination of high-intensity endurance and restriction to 150 minutes/wk of moderate-intensity training was recommended. DISCUSSION: The modified task force criteria are recommended for clinical decision-making, but clinical uncertainties remain in gene-elusive cases. Stress testing may complement current guidelines to unmask underlying cardiomyopathy. TAKE-HOME MESSAGE: Stress testing should be considered in athletes showing borderline features of ACM.