Left‐dominant arrhythmogenic cardiomyopathy with a nonsense mutation in DSP

A 74‐year‐old man had abnormal left ventricular (LV) function according to a perioperative test at a local hospital and was transferred to our institution for further evaluation and treatment. His electrocardiogram demonstrated the presence of premature ventricular contraction with a QRS complex of the right bundle branch block type and superior axis. His echocardiography showed systolic dysfunction of the LV (LV ejection fraction, 44.6%). Cardiac computed tomography imaging revealed banded and patchy densities observed frequently from the middle to epicardial layer of the LV wall. Cardiac magnetic resonance imaging showed fat signals on fat‐selective images and late gadolinium enhancement in the mid‐wall to subepicardial layers in the LV myocardium. Endomyocardial biopsy revealed the histological presence of fibrofatty replacement. A genetic analysis revealed a nonsense mutation in the desmoplakin gene. Thus, he was diagnosed with left‐dominant arrhythmogenic cardiomyopathy. To prevent fatal ventricular arrhythmias, an implantable cardioverter defibrillator was successfully implanted.