An Atypical "Hot-Phase" ARVC in a PKP2 Carrier

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a leading inherited cause of sudden cardiac death in young athletes. Rarely, ARVC may present with acute myocardial injury and troponin elevation, mimicking myocarditis and delaying diagnosis.

A 20-year-old competitive female cross-country runner presented with exertional presyncope and emesis during a race and was found to have marked troponin elevation. Electrocardiography demonstrated T-wave inversions in leads V₁ to V₃ and premature ventricular contractions. Evaluations for coronary and pulmonary embolism were negative. Transthoracic echocardiography demonstrated mild right ventricular dilation and dysfunction. Cardiac magnetic resonance revealed severe right ventricular dilation with an ejection fraction of 27% and extensive late gadolinium enhancement of the right ventricular free wall without left ventricular involvement. Genetic testing confirmed a pathogenic plakophilin-2 (PKP2) variant. A subcutaneous implantable cardioverter-defibrillator was placed, and competitive athletics was discontinued.

This case represents an atypical "hot-phase" presentation of PKP2-mediated ARVC with isolated right ventricular involvement and myocardial injury, distinct from the more common DSP-associated left-dominant phenotype.

ARVC should be considered in young athletes presenting with exertional syncope and troponin elevation. Cardiac magnetic resonance is critical for distinguishing ARVC from myocarditis.