Atrial flutter in the recipient atrium induced by premature beats arising from the donor atrium 10 years after orthotopic heart transplantation.

Background: Several mechanisms for the genesis of supraventricular arrhythmias in patients after orthotopic heart transplantation have been reported.

Results: We describe a 58-year-old male patient in whom atrial flutter occurred 10 years after orthotopic heart transplantation. During an electrophysiological study, bidirectional conduction between the recipient and donor atria was found. Atrial flutter in the recipient atrium was induced by programmed stimulation of the donor atrium using a single extrastimulus. The clinical symptoms were caused by atrial flutter arising from the recipient atrium with 1:1 to 3:1 conduction to the donor atrium. Mapping the anastomosis between the two atria indicated fragmented potentials at a discrete site of conduction. Delivery of radiofrequency energy at this site terminated conduction in both directions. Subsequent atrial pacing of the donor and recipient atria, respectively, demonstrated bidirectional conduction block.

Conclusions: Symptomatic arrhythmias in patients after heart transplantation can indirectly originate from the donor atrium via bidirectional recipient-donor atrial conduction. This type of arrhythmia can be successfully treated with radiofrequency ablation.