Radiofrequency catheter ablation in patients with symptomatic atrial flutter/tachycardia after orthotopic heart transplantation

Atrial arrhythmias are common phenomena after orthotopic heart transplantation.1,2 Atrial tachycardia or flutter originating from the donor heart is well recognized.3,4 Although it has been assumed that the recipient atrial myocardium is electrically isolated from that of the donor atrium by the atrioatrial anastomosis, some reports have demonstrated that clinical arrhythmias can arise from the recipient atrium due to the recipient-donor electrical conduction.5-15 Radiofrequency catheter ablat…

Radiofrequency catheter ablation in patients with symptomatic atrial flutter/tachycardia after orthotopic heart transplantation

Background Atrial tachycardia or flutter is common in patients after orthotopic heart transplantation.Radiofrequency catheter ablation to treat this arrhythmia has not been well defined in this setting. This study was conducted to assess the incidence of various symptomatic atrial arrhythmias and the efficacy and safety of radiofrequency catheter ablation in these patients.Methods Electrophysiological study and catheter ablation were performed in patients with symptomatic tachyarrhythmia. One Halo catheter with 20 poles was positioned around the tricuspid annulus of the donor right atrium, or positioned around the surgical anastomosis when it is necessary. Three quadripolar electrode catheters were inserted via the right or left femoral vein and positioned in the recipient atrium, the bundle of His position,the coronary sinus. Programmed atrial stimulation and burst pacing were performed to prove electrical conduction between the recipient and the donor atria and to induce atrial arrhythmias.Results Out of 55 consecutive heart transplantation patients, 6 males [(58 ± 12) years] developed symptomatic tachycardias at a mean of (5 ± 4) years after heart transplantation. Electrical propagation through the suture line between the recipient and the donor atrium was demonstrated during atrial flutter or during recipient atrium and donor atrium pacing in 2 patients. By mapping around the suture line, the earliest fragmented electrogram of donor atrium was assessed. This electrical connection was successfully ablated in the anterior lateral atrium in both patients. There was no electrical propagation through the suture line in the other 4 patients. Two had typical atrial flutter in the donor atrium which was successfully ablated by completing a linear ablation between the tricuspid annulus and the inferior vena cava. Two patients had atrial tachycardia which was ablated in the anterior septal and lateral donor atrium. There were no procedure-related complications. Patients were free of recurrent atrial tachyarrhythmias after a follow-up of (8 ± 7) months.Conclusions Four electrophysiological mechanisms have been found to contribute to the occurrence of symptomatic supraventricular arrhythmias following heart transplantation. Radiofrequency catheter ablation in patients with atrial flutter/tachycardia is feasible and safe after heart transplantation.