Biventricular Assist Device Support of a Child with Intractable Arrhythmias Secondary to Histiocytoid Cardiomyopathy

Abstract

Introduction Histiocytoid cardiomyopathy (HICMP) is a rare mitochondrial cardiomyopathy associated with intractable, life-threatening ventricular arrhythmias. Dilated, hypertrophic, and noncompaction phenotypes can also be seen with HICMP and have the potential to progress to heart failure. Heart transplantation (HT) and left ventricular assist device (VAD) support for heart failure in HICMP have been described in case reports, but there has been no published experience on Biventricular VAD (BiVAD) support for intractable arrhythmias in HICMP. Case Report A 13-month-old presented with lethargy, poor perfusion, and ventricular tachycardia (VT) with wide- and narrow-complex morphology. Ejection fraction was 54% with left ventricular (LV) noncompaction. Electrical and chemical rhythm control were unsuccessful, and rate control was complicated by symptomatic bradycardia. Rhythm control was transiently achieved with percutaneous stellate ganglion block, but the frequency of breakthrough ventricular fibrillation (VF) subsequently increased. PediMag® BiVAD with LV apical cannulation was implanted as a bridge to transplantation (BTT), with eventual conversion to Berlin Heart EXCOR® BiVAD. HICMP was confirmed by pathology at time of implant. Post-operative course was complicated by suction events, likely secondary to cannula position and underlying rhythm, as suction only occurred during systole in sinus rhythm. Suction events resolved with revision to left atrial cannulation. She continued to alternate between sinus rhythm, VF, VT, and asystole and intermittent “pauses” (no fill/no eject) were observed during sinus rhythm, likely due to competition from intrinsic ejection. She is now 4 months into BiVAD support with alternating sinus, VT, and VF rhythms, no device related complications, and excellent rehabilitation as she awaits HT. Summary We report our experience with BiVAD support of a 13-month-old with HICMP and intractable arrhythmias as BTT. In small children, it is important to understand the potential impact of cannula position and heart rhythm on device performance. Even in the absence of ventricular dysfunction, BiVAD support with atrial cannulation can provide excellent hemodynamic support for patients with HICMP and life-threatening arrhythmias.