Atypical Clinical Presentation of Arrhythmogenic Biventricular\nCardiomyopathy
A 57-year-old hypertensive woman presented with a 6-month history of atypical chest\npain. In addition, ongoing maintenance therapy with azathioprine for Crohn's disease and\na nonfunctional adrenal adenoma were observed. Family history was unremarkable, and\nphysical examination results were normal.\nElectrocardiography revealed a normal sinus rhythm, left axis deviation, and T-wave\ninversion in precordial leads from V2 to V6. Further, an epsilon wave in leads V1-V3\n() led to the suspicion of ARVC.\nMonitoring using a 24-h Holter electrocardiogram documented only occasional ventricular\nextrasystoles with left bundle branch block morphology and no significant cardiac\narrhythmia. Further evaluation included cardiac magnetic resonance (CMR) imaging, which\nrevealed right ventricular (RV) enlargement with an indexed end-diastolic volume of 110\nml/m2 and mild dysfunction (ejection fraction = 44%). No signs of fatty\ntissue infiltration were observed, but regional RV dyskinesia in the free wall and\noutflow tract was identified (). LV was\nmildly enlarged (90 ml/m2), and systolic function was at the lower limit of\nnormal. Flow analysis revealed no shunts in the aorta and pulmonary artery.\nSubepicardial delayed enhancement was observed the lateral basal and middle segments of\nLV as well as a small focal area of the RV free wall (). These findings suggested a diagnosis of ARVC with LV\ninvolvement.\nIn this case involving a patient with atypical symptoms, no clinical arrhythmia, and a\nnegative family history, three major criteria led to the definite diagnosis of ARVC:\ninverted T waves in the precordial leads in the absence of complete right bundle branch\nblock; epsilon wave in the right precordial leads; and regional RV dyskinesia with\nindexed end-diastolic volume ≥ 100 ml/m2.\nLV involvement in ARVC has been recognized in several studies and can occur in > 75%\npatients with disease progression.\nCMR is an ideal technique to aid in the diagnosis of this condition. Particularly, in asymptomatic patients,\nthe differential diagnosis of ARVC should be considered. Future investigations should\nclarify the clinical relevance of these findings and the prognosis of patients with\nbiventricular arrhythmogenic cardiomyopathy.