Introduction: A rapidly firing or triggered ectopic focus located within a pulmonary vein (PV) or close to the PV ostium could induce atrial fibrillation (AF). The aim of this study was to evaluate the efficacy and safety of a radiofrequency thermal balloon catheter for isolation of the PV from the left atrium (LA).
Methods and results: Twenty patients with drug-resistant paroxysmal AF were treated by isolating the superior PVs using an RF thermal balloon catheter. Using a transseptal approach, the balloon, which had an inflated diameter 5 to 10 mm larger than that of the PV ostium, was wedged at the LA-PV junction. It was heated by a very-high-frequency current (13.56 MHZ) applied to the coil electrode inside the balloon for 2 to 3 minutes, and the procedure was repeated up to four times. The balloon center temperature was maintained at 60 degrees to 75 degrees C by regulating generator output. Successful PV isolation was achieved in 19 of the 20 left superior PVs and in all 20 of the right superior PVs and was associated with a decrease in amplitude of the ostial potentials. Total procedure time was 1.8 +/- 0.5 hours, which included 22 +/- 7 minutes of fluoroscopy time. After a follow-up period of 8.1 +/- 0.8 months, 17 patients were free from AF, with 10 not taking any antiarrhythmic drugs and 7 taking the same antiarrhythmic agent as before ablation. Electron beam computed tomography revealed no complications, such as PV stenosis at ablation sites.
Conclusion: The PV and its ostial region can be safely and quickly isolated from the LA by circumferential ablation around the PV ostia using a radiofrequency thermal balloon catheter for treatment of AF.