Purpose: Electro-anatomic mapping (EAM) has been used for more than a decade to assist in defining arrhythmia propagation for transcatheter ablation. Intra-cardiac echocardiography (ICE) has also gained acceptance as an adjunct to further define intracardiac anatomy. The integration of these two technologies (CartoSound, Biosense-Webster, Diamond Bar, CA, USA) is a recent development. In this report, we describe our early experience in the young, with and without congenital heart defects (CHD).
Methods: The clinical and electrophysiologic records of the first 17 patients to undergo procedures with the CartoSound (EAM-ICE) system were reviewed. In all 17, the 3-dimensional shape of the chamber(s) of interest was created using serial tracing of ICE images. The ICE catheter was placed in the esophagus in three and through the femoral vein in 14. Descriptive analysis was performed on demographic data as well as procedural characteristics including procedure time, fluoroscopy time, geometry acquisition time, EAM duration, ablation time, procedure success, and complications.
Results: Arrhythmias comprised intra-atrial re-entry tachycardia (13 patients, 76%), Wolff-Parkinson-White syndrome (1; 6%), ventricular ectopic tachycardia (2; 12%), and atrioventricular node re-entrant tachycardia (1; 6%). Thirteen had CHD, with a median two palliative operations; six had single-ventricle anatomy. Procedure duration was 266 ± 134 min (median ± SD), and fluoroscopy time was 29 ± 28.3 min. Geometry acquisition took 41 ± 35.4 min, or 16% of the total case duration. Ablation lesions were placed in 16 cases, (cooled tip in 12) of which 15 (94%) were successful. One patient experienced mild hypotension. ICE image quality in three patients with the probe placed in the esophagus was suboptimal.
Conclusions: Advantages of CartoSound appear to be (1) anatomy modeling in the shape imposed by the arrhythmia, (2) more accurate geometry than EAM alone, and (3) demonstration of catheter position and lesions on echo during the study. Perceived disadvantages are (1) the large sheath required for ICE (11F), and (2) significant procedure time devoted to creation of anatomy. Optimal use may be to focus on key structures required for ablation, obtaining additional views as needed.