Reply to the Editor-Rhythmologic Challenges Following Heart Transplantation.

Three decades after its first description, heterotopic heart transplantation (HHTx) has fell into obscurity in most heart transplantation centers. Recent clinical publications on HHTx are scarce, although HHTx remains an important experimental model in the field of transplantation immunology. Nevertheless, several challenging conceptual and technical issues may arise in the management of HHTx survivors. In this perspective, we thought that describing a case of ventricular tachycardia ablation in an HHTx recipient in the modern era of 3-dimensional mapping might be useful. We fully agree with Sindermann et al, who stated that HHTx survivors should be closely monitored for ventricular arrhythmias (VAs), as the recipient heart with structural disease carries ventricular arrhythmogenic substrate, which may have worsened over time, and as VAs may be clinically silent or well tolerated, with the donor heart acting as a biological biventricular assistance, which was the case for the patient described in our report. Risk of VAs in HHTx has been described since the 1980s, but our report shows a contemporary management with electroanatomic mapping–guided catheter ablation.

In the developing era of mechanical assistance for end-stage heart failure, the question of the possible interests and contemporary indications of HHTx in selected patients with high pulmonary resistances or with size mismatch between the graft and the recipient is certainly debatable.2, 3 However, despite the long survival of the individual described in our report, we must state here that our report did not address this question and did not add evidence in favor of a broader use of HHTx.