Fusion of electrophysiology mapping data and angiographic images to facilitate radiofrequency ablation

Localization of target sites for radiofrequency catheter ablation (RFCA) is facilitated by the identification of abnormal electrograms at specific endocardial sites. With new 3-D electro-anatomical mapping systems such as the CARTO^TM system and the Real-time Positioning Management System^TM (RPM) the 3-D position of EP catheters can be visualized and recorded Detailed information about anatomical structures can only be obtained by standard imaging modalities, such as ventricular angiography. Combination of information obtained from the 3-D mapping systems with angiographic image information would therefore greatly enhance the applicability of these systems. In patients referred for ventricular tachycardia, the XYZ-coordinates of the ablation catheter positions, were obtained with the RPM system, and visualized in 3-D space. In addition, biplane angiographic images were obtained in these patients to confirm the geometric findings of the mapping system, and to display the ablation locations superimposed on the angiographic images. Analysis of the mapping and angiography data revealed that it is not feasible to create an accurate 3-D representation of a heart chamber based on two angiographic projections. Therefore, fusion of mapping data and angiographic images was not possible as planned. However, new ideas are presented that may make this fusion possible in the near future