Current Status of Atrial Fibrillation Ablation with Balloon Strategy.

Catheter ablation of atrial fibrillation (AF) has been established worldwide and is recommended for symptomatic paroxysmal AF patients according to international guidelines. Importantly, the cornerstone of any AF ablation represents pulmonary vein isolation (PVI). Traditional radiofrequency (RF) point by point ablation within a 3D electroanatomic left atrial (LA) map requires profound understanding of LA anatomy and electrophysiology. This ablation strategy can be highly efficient and safe if performed in experienced hands and centers. However, procedural complexity causes a long learning curve and has limited its wide spread utilization. In contrast, balloon based PVI ablation strategies are based on an anatomic principle. Currently, two balloon types (cryoballoon and laserballoon) have been adopted to clinical routine. Both balloons are positioned at the target PV and circumferential energy ablation is enabled. This simplified anatomic approach facilitates reaching the procedural endpoint of PVI and demonstrated less operator dependency. Therefore, balloon PVI appears to be associated with improved procedural reproducibility and safety. Importantly, large scale randomized trials proved non-inferiority of balloon guided AF ablation (cryothermal and laser energy) vs. experienced operators using traditional "gold standard" RF ablation in paroxysmal and persistent AF. Ongoing technological refinements of both balloons as well as the introduction of novel energy dosing strategies and ablation targets may potentially impact the current way of ablating AF in future. This review will summarize current clinical experience of contemporary balloon devices and will look into future developments.