Case summary:
A 21-year-old athletic male with a family history of unknown ventricular
arrhythmias, presented with near syncope, chest pain and exertional
palpitations. He had an initial work-up that was grossly unremarkable
including, electrocardiography (ECG), echocardiography and CMR imaging.
Six months later, he presented again with recurrent symptoms during
exercise and his ECG demonstrating a new epsilon wave. He had markedly
elevated cardiac biomarkers, (troponin I >100 ng/dl, normal
value < 0.04 ng/dl). A subsequent coronary angiogram was
performed, which was normal. Holter monitoring further showed subsequent
episodes of ventricular tachycardia with a right bundle branch
morphology. An endomyocardial biopsy was performed, which was negative.
A follow-up CMR demonstrated the new development and prominentleft ventricular epicardial scar in the lateral wall.
The patient underwent familial genetic testing, which confirmed the
presence of an isolated JUP gene mutation and showed multiple genes
consistent with ARVC in his mother. Thus, he manifested a partial
transmission of only one abnormal gene for ARVC and exhibited a markedly
different expression in his disease without evidence of typical
right-sided heart pathology. A third CMR study was performed, which
showed partial improvement in myocardial fibrosis after exercise
cessation.