Preserved electrical conduction between donor and recipient right atria as the cause of macroreentrant atrial tachycardia after heart transplantation.

Atrial arrhythmias after heart transplantation are common and usually originate from reentrant circuits inside the donor and recipient atria. A case is presented of macroreentrant atrial tachycardia with a reentry circuit incorporating preserved electrical conduction from the donor and recipient right atria. An invasive electrophysiological study including high-density electroanatomical mapping with a multipolar catheter was performed during tachycardia. A reentry circuit with an area of slow conduction at the supero-lateral aspect of the surgical anastomosis could be demonstrated. Catheter ablation at the site of slow conduction successfully terminated and permanently suppressed the tachycardia.