Radiofrequency catheter ablation of atrial flutter after orthotopic heart transplantation: Insights into the redefined critical isthmus

We report a case of successful radiofrequency catheter ablation of recurren t atrial flutter in a heart transplant recipient and discuss technical aspe cts of the procedure. A counterclockwise flutter circuit was defined during endocardial mapping of the donor atrium. Termination of atrial flutter was achieved by creating lines of radiofrequency lesions from the tricuspid ri ng to the suture Line between donor and recipient atria, Creation of bidire ctional conduction block in the tricuspid ring-suture line isthmus resulted in abolition of atrial flutter.