Real-time cardiac catheter navigation on three-dimensional CT images.

INTRODUCTION: Targets for ablation of atrial fibrillation, atrial flutter, and non-idiopathic ventricular tachycardia are increasingly being selected based on anatomic considerations. Because fluoroscopy provides only limited information about the relationship between catheter positions and cardiac structures, and is associated with radiation risk, other approaches to mapping may be beneficial.
METHODS: The spatial and temporal information of an electromagnetic catheter tip position sensing system (Magellan, Biosense Inc.) was superimposed on a three-dimensional (3D) CT of the chest in swine using fiducial markers for image registration. Position and orientation of a 6 French catheter with an electromagnetic sensor was displayed in real-time on a corresponding 3D-CT. Catheter navigation within the heart and the great vessels was guided by detailed knowledge about catheter location in relation to cardiac anatomy.
RESULTS: Anatomic structures including the atrial septum, pulmonary veins, and valvular apparatus were easily identified and used to direct catheter navigation. During the right heart examination, the catheter was navigated through the superior and inferior vena cava to predetermined anatomic locations in right atrium, right ventricle and pulmonary artery. The ablation catheter was also navigated successfully from the aorta through the aortic valve in the left ventricle. No complication was encountered during the experiments. The accuracy and precision of this novel approach to mapping was 4.69 +/- 1.70 mm and 2.22 +/- 0.69 mm, respectively.
CONCLUSIONS: Real-time display of catheter position and orientation on 3D-CT scans allows accurate and precise catheter navigation in the heart. The detailed anatomic information may improve anatomically based procedures like pulmonary vein ablation and has the potential to decrease radiation times.