Our laboratory is equipped with an EP MedSystems recording system (EP MedSystems, Inc., West Berlin, New Jersey), intracardiac ultrasound, and both Carto (Biosense Webster Inc., a Johnson & Johnson company, Diamond Bar, California) and EnSite NavX (St. Jude Medical, St. Paul, Minnesota) mapping systems.

AF Approach

For AF ablation, a classic activation map-guided semi-circumferential pulmonary vein isolation approach with the LASSO catheter (Biosense Webster Inc.) is used. Ablation lesions are placed at the outer pulmonary vein ostium, and if possible, pulmonary veins are isolated at the level of their common trunk. Additional right and left atrial linear ablations are performed only if sustained and organized right and/or left atrial flutters are induced and entrained after isolation of the pulmonary veins. Other organized arrhythmias are also targeted for ablation. However, left atrial linear ablation is avoided due to concerns of creating new arrhythmia substrates with incomplete lines. The majority of AF procedures are performed with the NavX system (St. Jude Medical), which allows the flexibility to use various catheters as well as visualization with the LASSO catheter. Preprocedural CT scans with three-dimensional (3D) reconstruction are used to understand PV anatomy; however, image integration is not routinely performed. Pulmonary venography and intracardiac echocardiography are used to define the location of the vein ostium. Residual organized tachycardias are routinely mapped with pacing maneuvers and entrainment mapping. Electroanatomical mapping is used with caution since it is often difficult to assign early and late electrograms in rapid atrial tachyarrhythmias, which frequently results in misleading activation maps.

Results

Our first 100 AF cases were performed under conscious sedation with a 4 mm non-irrigated RF catheter. Then we switched to an 8 mm tip catheter, and all of these cases were done under general anesthesia, which allows for esophageal visualization by barium esophagogram. Since routine intra-operative barium opacification of the esophagus was performed, the close relationship between the ablation site and esophagus particularly in the lower pulmonary veins became apparent. In cases of direct proximity of the ablation catheter to the esophagus, endoesophageal deflection with a TEE probe was attempted but found to be rather cumbersome.