Background: Thoracoscopic atrial fibrillation ablation (TARAFS) using irrigated bipolar radiofrequency energy (Medtronic Cardioblate Gemini -S) should result in wide isolation of the pulmonary veins (PVs) and posterior left atrial (LA) wall (the box-lesion technique). Electrophysiological findings after this technique using this instrumentation are not known.
Methods and results: 22 patients with AF recurrence after bilateral TARAFS for persistent AF had a radiofrequency catheter ablation (CA) at least three months after TARAFS.
Results: Out of 22 patients, the box lesion was not completed in 15 (68.2 %) patients. 12 had no endocardial signs of any prior ablation, 2 had right pulmonary PVs isolated and 1 had left PVs isolated. At the end of CA, box lesion was finished in all 15 patients and AF non-inducibility was achieved in 18 patients. 19 patients (86.4 %) were free of any atrial tachyarrhythmia with/without AADs and with/without repeated ablation (1.18 ablation/patient).
Conclusion: In a considerable number of patients with AF recurrence after TARAFS box lesion is not finished and no signs of prior ablation to guide a touch-up catheter ablation are found on electroanatomical voltage map. In majority of patients, additional ablation beside box lesion is needed to achieve AF non-inducibility.