BACKGROUND: Cryoballoon apposition is crucial for durable pulmonary vein isolation (PVI) in atrial fibrillation, yet the balloon is difficult to visualize by conventional mapping systems, and pulmonary venography may miss small or out-of-plane leaks. We report a novel imaging system that offers real-time 3-D navigation of the cryoballoon within atrial anatomy that may circumvent these issues.METHODS AND RESULTS: A novel overlay guidance system(OGS) (Siemens Healthcare, Forchheim, Germany) registers already-acquired segmented atrial cardiac tomography (CT) with fluoroscopy, enabling real-time visualization of the cryoballoon within tomographic left atrial imaging during PVI. Phantom experiments in a patient-specific 3D printed left atrium showed feasibility for confirming PV apposition and leaks. We applied OGS prospectively to 68 PVs during PVI in 17 patients. The cryoballoon was successfully reconstructed in all cases, and its apposition was compared to concurrent PV venography. The OGS uncovered leaks undetected by venography in 9 veins (8 cases) which enabled repositioning, confirming apposition in remaining 68 veins. Concordance of OGS to venography was 83.8% (chi2 , p<0.01) CONCLUSIONS: We report a new system for real-time imaging of cryoballoon catheters to ensure PV apposition within the tomography of the left atrium. While providing high concordance with other imaging modalities for confirming balloon apposition or leak, the system also identified leaks missed by venography. Future studies should determine if this tool can provide a new reference for cryoballoon positioning. This article is protected by copyright. All rights reserved Cryoballoon ablation is increasingly used for pulmonary vein isolation (PVI), but it may be difficult to track cryoballoon position relative to the PV for complete occlusion. We describe a novel overlay guidance system (OGS) for real-time 3D visualization of the cryoballoon within atrial anatomy, by registering atrial computed tomography in 2 fluoroscopic planes. Phantom experiments with a custom 3D printed left atrium showed feasibility for visualizing balloon apposition within PVs. In 68 PVs in 17 patients, the OGS prospectively identified cryoballoon position relative to PVs, and uncovered leaks undetected by venography. Future studies should test if the OGS can serve as a new reference for cryoballoon positioning.
View details for DOI 10.1111/pace.13858
View details for PubMedID 31868241