Po-02-121 impact of pulmonary vein ovality and occlusion status measured by the novel dielectric-based mapping system on acute vein isolation during cryoballoon ablation

Cryoballoon ablation (CBA) has been widely accepted as a major technic for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). PV anatomy is an important factor to obtain circumferential balloon adhesion that results in vein occlusion to achieve acute PVI. The KODEX-EPD (Philips, Amsterdam, Netherlands) is a dielectric-based electroanatomic mapping system that can display a panoramic (PANO) view of the left atrium and evaluate PV occlusion without other imaging modalities. Prior studies demonstrated that high PV ovality is the potential mechanism of impeding the formation of durable lesion. However, the accuracy of PV ovality assessed by KODEX-EPD system and how it influences the performance of the PV occlusion tool and acute PVI are still unknown. To assess the PV occlusion and PV ovality using the KODEX-EPD system, and to evaluate the accuracy of them and their impact on acute PVI. We enrolled 10 patients who underwent primary CBA for paroxysmal AF using KODEX-EPD system, all of them had a pre-procedural cardiac CT or MRI. Ovality index (OI) was defined as the ratio of the PV maximum diameter divided by PV minimum diameter which was measured by KODEX-EPD system under PANO view and on CT/MRI images under sagittal view. An evaluation of PV occlusion was obtained using the KODEX-EPD Occlusion Viewer and intracardiac echography on each CB-PV engagement. Single shot PVI was defined as the isolation of PV at the first freezing attempt after complete occlusion of the PV. Fifty-eight balloon-PV engagements in 39 PVs were analyzed. Consistent occlusion status between KODEX and ICE were obtained in 50 (86%) engagements [complete occlusion: 30/34 (88%), incomplete occlusion 20/24 (83%)]. The OI of PV with incomplete occlusion by KODEX is significantly larger than that with complete occlusion (2.0±0.5 vs 1.6 ±0.4. p=0.03). Representative cases are shown in Figure1A and B. Single shot PV isolation was achieved in 33 of 39 PVs (84%). All of them showed complete occlusion status in KODEX, and OI of PV with single shot isolation was significantly smaller than that without single shot isolation (1.6±0.4 vs 2.1±0.4, p=0.003). A positive correlation was found between the OI measured by KODEX and CT/MRI (Figure1C). The evaluation of PV anatomy and occlusion status using the novel dielectric-based mapping system is feasible and may facilitate CB ablation of AF. Higher PV ovality is associated with incomplete PV occlusion and lower acute PVI rate.