Clinical experience with electroanatomic mapping of ectopic atrial tachycardia.

The aim of this study was to evaluate the clinical use of a new three-dimensional mapping system as a guide for catheter ablation of ectopic atrial tachycardia. A series of 42 consecutive patients with drug refractory ectopic atrial tachycardia was studied in a prospective observational trial with the electroanatomic mapping system CARTO. The arrhythmogenic focus was found in the right atrium in 30 patients and in the left atrium in 12 patients. The construction of a complete electroanatomic map of the right or left atrium was possible in 37 of 42 consecutive patients with ectopic atrial tachycardia. Mean activation time of the right atrium, including the proximal coronary sinus, was 94 +/- 25 ms for right atrial tachycardias; left atrial activation time during left atrial tachycardias was 86 +/- 17 ms. Average mapping time was 30 minutes for right atrial tachycardias and 22 minutes for left atrial tachycardias, allowing the collection of 86 +/- 50 and 65 +/- 28 catheter positions, respectively. The size of the area of earliest atrial activation calculated from the electroanatomic map amounted to 0.6 +/- 0.4 cm2 in right atrial tachycardias and 1.0 +/- 0.9 cm2 in left atrial tachycardias. In the right atrium the most common locations of the 33 arrhythmogenic foci in 30 patients were the high or mid-lateral right atrium (n = 10) and the inferoparaseptal region near the coronary sinus ostium (n = 7). Ectopic left atrial foci were most commonly located in an inferior position near the mitral annulus (n = 5) and in proximity to the ostium of the pulmonary veins (n = 4). Biatrial electroanatomic mapping allowed visualization of earliest right atrial activation during left atrial tachycardia at the high interatrial septum or near the coronary sinus ostium. Catheter ablation was successful in 85% of right atrial tachycardias and 82% of left atrial tachycardias. In patients with ectopic atrial tachycardia electroanatomic mapping is a safe and feasible technique that allows three-dimensional visualization of the automatic focus in a precise anatomic reconstruction of the atria. This novel mapping technology facilitates catheter ablation of complex ectopic atrial tachycardia.