Introduction
During the past decades, catheter ablation has been an established curative treatment for atrial fibrillation (AF), with pulmonary vein isolation (PVI) as its cornerstone1, 2. Cryoballoon ablation (CBA) is a promising tool for achieving PVI, and its safety and efficacy have been extensively investigated3-6. In CBA procedure, optimal occlusion of the inflated balloon to each pulmonary vein (PV) antrum is essential for achieving adequate tissue lesions and durable PVI. To date, PV occlusion is assessed by contrast medium injection through the central lumen of the cryoballoon (CB), which increases contrast dose and radiation exposure.
The KODEX-EPD system (EPD Solutions, a Philips Company) is a novel 3-dimentional navigation system7, 8, which was shown to be feasible to reconstruct high-resolution left atrial (LA) images, and to facilitate CBA procedure9. In addition, the occlusion verification software integrated in the system has recently been demonstrated to provide accurate and real-time information of occlusion degree of CB10, 11, thus significantly reduce contrast use and radiation exposure in CBA procedure12. In the latest version of this system, there are two tools, the baseline tool and the injection tool, available to facilitate the process of occlusion assessment. However, the accuracy of the two tools has not been systematically evaluated.
The purpose of the present study was to investigate the performance of the two different tools for PV occlusion assessment with KODEX-EPD mapping system in CBA procedure for AF.