Dynamic registration of preablation imaging with a catheter geometry to guide ablation in a Swine model: validation of image integration and assessment of catheter navigation accuracy.

BACKGROUND: Catheter ablation of atrial and ventricular tachyarrhythmia involves anatomically based cardiac ablation strategies. CT and MRI images provide the most detailed cardiac anatomy available. Integration of these images into a mapping system should produce detailed and accurate models suitable to guide ablation.
OBJECTIVE: The purpose of this study was to validate and assess the accuracy of a novel CT and MRI image integration algorithm designed to facilitate catheter navigation and ablation.
METHODS: Using a lateral thoracotomy, markers were sutured to the epicardial surface of each cardiac chamber in 12 swine. Detailed CT/MRI anatomy was imported into the mapping system. The CT/MRI image was then integrated with a detailed catheter geometry of the relevant chamber using a new image integration algorithm. The epicardial markers, identified from the CT/MRI images, were then displayed on the surface of the integrated image. Guided only by the integrated CT/MRI, a single RF lesion was directed at the corresponding endocardial site for each epicardial marker. At autopsy, the distance from the endocardial RF lesion to the target site was assessed.
RESULTS: The mean position error (CT/MRI) for the left atrium was 2.5 +/- 2.4 mm/5.1 +/- 3.9 mm, for the right atrium 6.2 +/- 6.5 mm/4.3 +/- 2.2 mm, for the right ventricle 6.2 +/- 4.3 mm/6.6 +/- 5.3 mm, and for the left ventricle 4.7 +/- 3.4 mm/3.1 +/- 2.7 mm. There was no cardiac perforation or tamponade.
CONCLUSION: CT and MRI images can be effectively utilized for catheter navigation when integrated into a mapping system. This novel registration module with dynamic registration provides effective guidance for ablation.