To the Editor- Rhythmologic challenges following heart transplantation.

Heterotopic heart transplantation (hHTx) was first performed in humans in 1974. It found its way into broader application in the late 1980s and early 1990s, especially for patients with elevated pulmonary vascular resistance. Laredo et al1Laredo M. Varnous S. Balagny P. Leprince P. Hidden-Lucet F. Duthoit G. Successful catheter ablation of recipient left ventricular tachycardia 26 years after heterotopic heart transplantation.HeartRhythm Case Rep. 2017; 3: 159-163Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar have recently described a case of successful catheter ablation of ventricular tachycardia in a patient 26 years after hHTx. This article is of particular interest for 2 reasons. First, it describes the challenging approach of performing catheter ablation in a setting of hHTx, especially for ventricular arrhythmia, which is only scarcely described in the literature. Second, the authors casually mention a case of internationally remarkable survival of 26 years after hHTx. In our center we have performed hHTx in 1 child and 16 adult patients. The child showed cardiac recovery, allowing explantation of the transplanted heart about 4 years after hHTx.2Schmid C. Kececioglu D. Konertz W. Möllhoff T. Scheld H.H. Biological bridging after repair of an anomalous origin of a left coronary artery.Ann Thorac Surg. 1996; 62: 1839-1841Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar Four of the 16 adult patients displayed long-term survival of >10, >13, or >18 years, including 1 patient of 27 years survival by now. In 2 cases we faced complex ventricular arrhythmias, which were treated by medication/cardioversion, by an implantable cardioverter-defibrillator previously implanted in the native heart, or by external defibrillation.3Engelen M.A. Stypmann J. Bittner A. Scheld H.H. Sindermann J.R. Breithardt G. Eckardt L. Complex ventricular arrhythmias in patients after heterotopic heart transplantation.Int J Cardiol. 2011; 152: e9-e11Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar Even in orthotopic HTx, arrhythmias can be challenging as described for catheter ablation of atrial tachycardia because of recipient-to-donor transatrial conduction.4Ribbing M. Mönnig G. Wasmer K. Breithardt G. Eckardt L. Catheter ablation of atrial tachycardia due to recipient-to-donor transatrial conduction after orthotopic heart transplantation.Europace. 2004; 6: 215-219Crossref PubMed Scopus (15) Google Scholar Taken together, we fully support the article by Laredo et al1Laredo M. Varnous S. Balagny P. Leprince P. Hidden-Lucet F. Duthoit G. Successful catheter ablation of recipient left ventricular tachycardia 26 years after heterotopic heart transplantation.HeartRhythm Case Rep. 2017; 3: 159-163Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar with the messages that hHTx is capable of showing considerable survival in selected cases. We further stress that follow-up of patients who underwent HTx should comprise rhythmologic expertise since such patients have the potential to develop complex as well as HTx-specific and rarely seen arrhythmias. Successful catheter ablation of recipient left ventricular tachycardia 26 years after heterotopic heart transplantationHeartRhythm Case ReportsVol. 3Issue 3PreviewIn heterotopic heart transplantation (HHTx), the donor heart is connected to the recipient heart in a parallel fashion, acting as a biological biventricular assist device. This technique has been developed before the cyclosporine era to reduce early postoperative death related to graft failure. HHTx is associated with a lower long-term survival compared with orthotopic heart transplantation and is now only used for selected patients with high pulmonary vascular resistance as an alternative to heart-lung transplantation or in case of major donor-to-recipient size mismatch. Full-Text PDF Open AccessReply to the Editor—Rhythmologic Challenges Following Heart TransplantationHeartRhythm Case ReportsVol. 3Issue 12PreviewThree 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. Full-Text PDF Open Access