Atrial resynchronization following heart transplantation in childhood

Despite preserved left ventricular function, exercise capacity is often impaired after cardiac transplantation due to autonomic denervation of the donor's sinus node. We present our experience with atrio-atrial resynchronization in 2 pediatric heart transplant recipients. Both were highly active, suffered from chronotropic incompetence, and underwent successful atrial resynchronization with an objective improvement in exercise capacity, restoration of a physiologic chronotropic response, and resolution of dyspnea. Long-term stable recipient sinus node function may, therefore, be maintained in some cardiac transplant recipients with standard atrio-atrial anastomes. Atrio-atrial pacing may be feasible and effective years after transplantation.