A 50-year-old man, 2 years post–heart transplantation, presented with progressive mild shortness of breath on follow-up. Echocardiography revealed normal left ventricular (LV) and right ventricular (RV) systolic functions, no valve abnormalities, and an echogenic mass (A [blue arrow]) encroaching the LV apex (Online Video 1). Chest radiographs confirmed the new mass in the left costophrenic angle, comparing immediately after transplantation (B) and 2 years after transplantation (C [blue arrow]).

Cardiac magnetic resonance (CMR) imaging revealed a large mass (D [blue arrow]) outside the LV apex, with signal intensities consistent with fat, without suspicious invasive features (Online Video 2). Detailed assessment demonstrated that this fat originated in the abdominal cavity, passing through a lateral diaphragmatic hernia (E [yellow arrow];Online Video 3). This, in turn, was secondary to the bridging ventricular assist device before transplantation, best shown on a pre-transplantation computed tomography (CT) scan (F). The patient was managed conservatively, with no immediate plan for herniorraphy. With the widespread use of ventricular assist devices, iatrogenic diaphragmatic hernia is increasingly recognized.