Electrophysiological findings after bilateral thoracoscopic atrial fibrillation ablation using irrigated bipolar radiofrequency energy

Abstract

Abstract Background Thoracoscopic atrial fibrillation (AF) ablation (TARAFS) using irrigated bipolar radiofrequency energy should result in posterior left atrial (LA) wall isolation. Purpose To assess the long-term durability of this “box” lesion and the extent of additional ablation needed to achieve AF non-inducibility. Methods 22 patients with AF recurrence after bilateral TARAFS for persistent AF had a radiofrequency catheter ablation (RFA) at least three months after TARAFS. Electroanatomical voltage map was done in all patients prior to any ablation. Results Out of 22 patients, the box lesion was not completed in 15 (68.2%). In these 15 patients, 12 had no signs of any prior ablation in endocardium (voltage >0.5mV), 2 had right pulmonary veins (PVs) isolated and 1 had left PVs isolated. At the end of RFA, box lesion was finished in all 15 patients and AF non-inducibility was achieved in 18 patients. For this endpoint, besides box lesion, mitral line and extensive coronary sinus ablation was necessary in 14, extensive CFAE ablation in 7 patients. Cavotricuspid isthmus line block was done in all patients. Conclusion A minimally invasive thoracoscopic box-lesion ablation is considered to be a safe and effective method of stand-alone AF treatment. However, in a considerable amount of patients no signs of prior ablation are found on electroanatomical voltage map. Gaps thus cannot be found and a completely new complex ablation must be done. In a lot of patients, additional ablation is needed besides box lesion to achieve non-inducibility. Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): University Hospital Olomouc