Background: In cryoablation of atrial fibrillation, we prefer using a 0.035-inch guidewire as a rail for the cryoballoon rather than a mini-lasso catheter. The guidewire can be passed selectively into a specific side branch of the target vein branches to allow more coaxial orientation of the cryoballoon, and thereby superior occlusion of the pulmonary vein (PV).
Purpose: Endocardial Solutions Inc.’s (ESI) three-dimensional (3D) mapping system can localize a coil-tip guidewire in three dimensions and determine location in the appropriate side branch as well as the PV, which we hypothesized would facilitate cryoisolation.
Methods: The study population included 26 patients (19 men) with paroxysmal atrial fibrillation who underwent cryoballoon PV isolation (mean age 65 ± 9 years, mean left atrial volume index 37.4 ± 11 ml/ m², mean left ventricular ejection fraction 56 ± 10%). Following transseptal puncture, the 0.035-inch guidewire was passed into the target branch and then into its various side branches. An alligator clip connected the guidewire to the ESI 3D system. Surface patches served as ESI reference.
Results: By comparing preoperative left atrial computed tomography scan side by side with the ESI 3D map of the target branch and its side branches, it was possible to determine the location of the target PV and side branches more quickly and conveniently than occlusive venography. When complete balloon occlusion of the PV could not be achieved, introducing the guidewire into an alternate side branch allowed isolation.
Conclusion: Guidewire localization with the ESI 3D system is helpful in cryoballoon ablation by allowing rapid identification of the target vein and selection of the best PV side branch for placement of the support guidewire to allow better PV occlusion