Introduction: Preprocedural cardiac imaging (CT/MRI) and intraprocedural electroanatomical mapping (EAM) are commonly used during left atrial (LA) catheter ablation of atrial fibrillation (AF). In the optimal scenario, the imaging datasets would be directly integrated with the EAM system to guide catheter mapping based on the accurate individual cardiac anatomy.
Methods and results: Strategies to align the EAM and imaging data were assessed by simulations using a life-size model of the LA and aorta. This revealed that the optimal strategy includes mapping both the aorta and LA. Respiratory changes in cardiac anatomy were evaluated by MR angiography performed in 10 patients during both inspiration and expiration. Comparison of paired images revealed inferior and anterior movement of the LA relative to the aorta with inspiration. Next, image integration was employed in a series of patients (n = 13) scheduled for AF catheter ablation. After preprocedural CT angiography (7 during inspiration and 6 during expiration), three-dimensional anatomical renderings of these images were integrated with the EAM data in a custom workstation to permit real-time catheter manipulation within these constructs. The electrophysiologist was blinded to these integrated images, but the accuracy of the process was assessed real-time by a second operator. This revealed poor alignment during inspiration but good alignment during expiration--the respiratory phase most closely resembling that during EAM.
Conclusions: This study supports the feasibility of integrating preacquired cardiac images with real-time electroanatomical mapping to guide catheter movement in the LA in a reliable and clinically relevant manner.