Clinical experiences with cooled radiofrequency ablation of ectopic atrial tachycardia employing an electroanatomic mapping system

Due to its variable origin success for ablation of ectopic atrial tachycardia (EAT) has been difficult to achieve using conventional mapping and ablation strategies. In contrast, no information in the literature is available about the use of a non-fluoroscopic, 3-dimensional electroanatomic mapping system (CARTO™) combined with the cooled ablation technology creating deeper lesions in experimental studies compared to standard catheters. In 20 consecutive patients (15 female; age 52.5±15.4 years), a single focus responsible for clinical EAT has been mapped. Twelve EATs were located in the right atrium, whereas 8 foci were left sided including 3 origins within a pulmonary vein (PV). Due to the reported development of PV stenosis in the ablative treatment of focal atrial fibrillation, direct ablation applied inside the PV was avoided. Instead, PV-disconnection achieved by the use of a Lasso™ catheter in 1 case and by circumferential ablation around the PV in 2 other patients was preferred. In 2 patients, ablation was not attempted because of an origin located directly in the area of the atrioventricular node. In another case, CARTO™ mapping was stopped due to persistent mechanical termination of the tachycardia with no possibility of reinduction. In the latter, ablation was performed in sinus rhythm at the earliest mapped site before terminating. Three weeks later another episode of EAT was noted in this patient. In the remaining 17 cases, ablation was associated with acute success and no recurrences of sustained tachycardia in all patients. Mean duration time was 192±53.3 min (right atrium 161±37.9 min; left atrium 229.6±46.2 min), and average fluoroscopic time was 22.8±9.7 min (right atrium 17.1±6.2 min; left atrium 29.8±8.9 min). There was no incidence of serious complications associated with this procedure. In conclusions, electroanatomical mapping including cooled ablation was a safe and feasible strategy in treating EATs. The benefit of this technique may imply the combination of both precise localization of the focus and effective applications of radiofrequency pulses, thereby minimizing acute failures or reablation. Due to the time consuming point by point data acquisition, the ability to generate precise maps demonstrating the earliest activation at their exact anatomical location can be limited by transient or persistent termination of the tachycardia.