The Role of Angle in the Evaluation of Ablation Accuracy in Pulmonary Vein Isolation Navigated by Image Integration

Background: The conventional index for ablation accuracy is to compare the distance between mapping points with and without treatment by using image integration. We attempted to quantitatively evaluate the role of angle as an index in the ablation accuracy in patients with atrial fibrillation (AF). Methods: A total of 48 patients with AF were included in the present study. Virtual fluoroscopy planes were predicted by pulmonary vein (PV) angiography, and the standard image planes were defined on the basis of the computed tomography images. Ablations were performed, guided by image integration; and the ablation planes were defined by the actual ablation rings. The predicted angle (distance) was defined as the angle (distance) between the fluoroscopy (predicted) plane and image (standard) plane, whereas the actual angle (distance) was defined as the angle (distance) between the ablation (actual) planes and the image (standard) planes. Results: We found that all actual angles were significantly smaller than the predicted angles (P <. 05), but only the actual distances in the left PV, right inferior PV, right superior PV, and right PV were significantly smaller; the distances in the left inferior PV and left superior PV were not significantly different (P >. 05). Conclusion: Our finding indicates that both the angle and the distance can be significantly reduced by navigation with image integration, but that the angle exhibited better sensitivity than the conventional index of distance. We suggest that the angle should be considered as a new index for ablation accuracy.