P943Ablation of atrial tachycardia originating from a donor common trunk of the left pulmonary veins after bilateral lung transplant - Case report

Abstract

Introduction: Atrial tachyarrhythmias have been described during the early and late course of heart or lung transplantation. Bilateral lung transplant can be seen as the ultimate form of antral isolation of the pulmonary veins and may provide long-term freedom from atrial fibrillation. However, this process leaves behind anastomotic lines that can serve as potential substrate for reentrant or focal tachycardias. The following case exemplifies two types of atrial arrhythmias that can manifest late after lung transplant. Methods and Results: A 47-year-old man with chronic obstructive lung disease underwent bilateral lung transplantation in 2013 due to respiratory insufficiency. He had no prior history of arrhythmias or structural heart disease. On extracorporeal membrane oxygenation the donor's pulmonary veins with the surrounding left atrial cuff were sewn to the corresponding area of the recipient's left atrium. In 2015, the patient developed frequent episodes of symptomatic palpitations. ECG showed paroxysmal atrial tachycardia with a cycle length of 400 ms and 2:1 conduction to the ventricle. Medical therapy (flecainide, bisoprolol) and DC-cardioversion did not suppress the tachycardia. EP study including detailed 3D-electroanatomical mapping revealed a focal atrial tachycardia originating from the donor left pulmonary vein ostium. Multipolar circular mapping localized earliest activation in the recipient cuff adjacent to the lower anastomosis of the left common trunk where continuous low-amplitude high-frequency signals were evident (figure). The activation wave front crossed the anastomosis line between the donor left inferior pulmonary vein and the recipient left atrium. Efforts to entrain the tachycardia in the area failed to elicit atrial capture. The left common trunk was successfully isolated with cooled radiofrequency ablation (30 W) along the ridge, which restored sinus rhythm. Thereafter, cavotricuspid isthmus-dependent right atrial flutter (CL 300 ms) was induced and ablated successfully with confirmation of bidirectional block. The patient remained free of recurrent atrial arrhythmias off antiarrhythmic drugs during long-term follow up. Conclusions: The surgery in bilateral lung transplantation creates a surgical pulmonary vein isolation at the antral level that provides usually freedom from atrial fibrillation but creates anastomotic lines of block that can facilitate the occurrence of atrial flutter. In our case, a partial reconnection between the recipient left atrium and donor left common trunk was found to be the source of a pulmonary vein-mediated atrial tachycardia, probably due to microreentry, which can be treated successfully with pulmonary vein isolation. (Figure Presented).