Second Presentation:
Six-months after the initial presentation, the patient again presented to the emergency department with severe, sharp, mid-substernal chest pain with associated diaphoresis, and lightheadedness. He remained physically active including frequent exercise. Physical exam including orthostatic vitals was unremarkable. Electrocardiogram showed sinus bradycardia at 40 bpm without ST elevation or depression and a right ventricular conduction delay with an epsilon wave (Image 2), which were new findings compared to prior. Troponins continued to rapidly and markedly increase in addition to elevations of transaminases and inflammatory markers (Table 1). Infectious work-up including covid-19 PCR was negative. Cardiac angiography revealed no coronary artery disease but a very prominent mid LAD myocardial bridge with near complete obliteration at resting HR in 70s. A repeat echocardiogram showed a new reduction in EF to 40-45% and diffuse hypokinesis of the LV (in comparison to six months earlier).
A repeat CMR three months after the previous scan (2ndCMR study) revealed new findings of mildly reduced LV systolic function with mild-moderate hypokinesis of the mid to apical lateral wall, and prominent epicardial fibrosis and an area of small, focal mid-myocardial fibrosis in a non-ischemic pattern with elevated native T1 and T2 values on mapping, respectively (Image 4). Of note, the study still did not meet any CMR criteria for ARVC. The patient subsequently received an endomyocardial biopsy without any significant histologic changes reported. Genetic testing demonstrated one pathogenic variant in the JUP gene in our patient, along with multiple genetic abnormalities for ARVC in his mother including abnormal JUP, NEBL and ACTN2 genes. Given these genetic results along with his family history, the patient was referred for an ICD implant for primary prevention of sudden cardiac death along with exercise limitation. A follow-up (3rd CMR scan) was performed after 11 months after initial CMR scan, which showed improvement in myocardial fibrosis (Image 5).