Tachyarrhythmias after pediatric heart transplantation

Tachyarrhythmias in pediatric post-heart transplant patients are not well defined. In this study we sought to further characterize these arrhythmias in terms of presentation, course, and outcome.

This investigation was a retrospective review of heart transplant recipients at St. Louis Children's Hospital during the period of 1991 to 2006. Patients were excluded if they were >18 years at transplantation or if follow-up information was unavailable. Patients with tachyarrhythmias beyond the first 2 weeks post-transplant were identified.

Twenty-eight tachyarrhythmias occurred in 25 of 237 heart transplant recipients. Freedom from arrhythmia was 92% at 1-year post-transplant and 86% at 15 years post-transplant. Intra-atrial reentry tachycardia (12 patients) and ectopic atrial tachycardia (10 patients) were the most common arrhythmias. Rejection was found in 3 (12%) and previously unrecognized coronary disease was found in another 2 (8%) at the time of presentation with arrhythmia. Fifteen of 25 (60%) were asymptomatic at presentation, but 4 of 25 (16%) presented with heart failure, including 3 without evidence of rejection. No risk factors for developing arrhythmia were identified. Twenty-one arrhythmias resolved with brief pharmacologic or no therapy. Only 3 had a recurrence after the initial arrhythmia. Five patients underwent catheter ablation.

Our experience suggests that the presence of tachyarrhythmias after pediatric heart transplantation is not rare and usually not associated with rejection. Pediatric heart transplant recipients have a higher incidence of ectopic atrial tachycardia (EAT) than their adult counterparts. Most tachyarrhythmias resolve after a relatively brief period of medical treatment and recurrence is uncommon.