1 INTRODUCTION
With respect to efficacy, cryoballoon (CB)-guided pulmonary vein (PV) isolation of paroxysmal atrial fibrillation (AF) can provide a comparable1-4 or better outcome than contact force-guided radiofrequency catheter ablation.5 Thus, CB ablation is clearly one of the most effective treatment modalities for AF.6,7 However, CB application connotes the risk of severe PV stenosis/occlusions,8,9 and may damage to the extracardiac structures such as the esophagus,10phrenic nerve, and bronchus.11,12
Chun et al. reported the “crosstalk” (CST) phenomenon in which CB application of the left inferior PV (LIPV) was able to ablate the gap sites along the inferior aspect of the left superior PV (LSPV) when applications failed to isolate the LSPV.13 This CST ablation technique can be beneficial in terms of reducing unnecessary freezing of the atrial tissue. Nevertheless, it is unclear which situations will necessitate the adoption of the CST ablation technique. Miyazaki et al. showed that the CST ablation technique was useful in cases in which the LSPV could not be isolated even if complete PV occlusion was achieved with the CB, and the nadir balloon temperature (NT) of the CB was not fully analyzed.14
The present study aimed to investigate the relationship between the NT and occlusion status of the CB and the efficacy of CST ablation. Additionally, we sought to find the predictors of appropriate conditions for when the CST ablation technique should be adopted.