Clin Res Cardiol (2022).

Initial experience with Pulsed field ablation of complex atrial tachycardia
B. Schäffer1, M. A. Gunawardene1, M. Jularic1, C. Eickholt1, T. Maurer1, R. Ö. Akbulak1, O. Anwar1, N. Geßler1, J. Hartmann1, S. Willems1
1Kardiologie, Asklepios Klinik St. Georg, Hamburg;

Background: Pulsed field ablation (PFA) is a novel technology for ablation of atrial fibrillation (AF). Pulmonary vein isolation (PVI) promises to be highly effective, however there is no data regarding ablation of consecutive atrial tachycardias (AT).


Objective: This study sought to investigate and PFA-based ablation of consecutive AT following prior catheter ablation (CA) of AF in conjunction with the use of ultra-high-density (UHDx) mapping. 


Methods: Consecutive patients underwent UHDx mapping (OrionTM catheter and RhythmiaTM Mapping system, Boston Scientific) and ablation of AT. Subsequent to identification of the AT mechanism, the assumed critical isthmus and optimal PFA target sites, ablation was performed using a multispline catheter (Farwave, Farapulse Inc) aiming to create continuous ablation lines. Additional ablation, including repeat PVI and left atrial posterior wall isolation (LAPWI) was performed if required or rational. Extent of PFA-lesions and block of lines were assessed with pre- and post PFA UHDx-mapping.


Results: Six patients with AT (age 65±13, male 83%) who underwent 5±2 prior left atrial (LA) catheter ablation procedures were included. Total mean procedure and LA PFA times were 162±52 and 44±10 minutes, respectively. Mean total fluoroscopy and LA PFA fluoroscopy times were 21±12 and 10±2 minutes, respectively. Nine ATs with a cycle length of 355±149 ms were mapped and targeted of which one CS-ostium AT and one common type atrial flutter were ablated with conventional RF technology. One micro reentry AT (LAA-ridge) and 6 macro-reentry AT (4 LA anterior, 1 posterior, 1 perimitral flutter) were targeted with PFA. All AT terminated with ablation either to sinusrhythm (3/6 cases) or a secondary AT (3/6 and subsequently to SR). Anterior line ablation was performed in 4/6 cases, roofline ablation in 5/6 cases (4 cases including LAPWI), LAA isolation was achieved in one case. A total of 34±10 PFA applications were required. PV-reconnection was found in 2 patients. Yet, repeat PVI of at least 1 PV was performed in 5/6 cases to anchor lines, complete LAPWI, extend antral PVI area or target ostial potentials along the initial ablation line, requiring 17±13 PFA applications. Repeat UHDx mapping in sinus rhythms revealed isolated LAPW in 3/4 cases, with additional ablation required in one patient to complete LAPWI. Anterior lines and roof lines were completed in all cases demonstrated by 3D-mapping. Esophageal endoscopy was performed in all patients with LAPWI without any lesion detection. One aneurysm at the puncture site occurred and required thrombin injection. No further complications occurred.


Conclusion: PFA of consecutive left atrial tachycardias is feasible and safe. Successful creation of ablation lines and left atrial posterior wall isolation with PFA can be achieved in a short time. PFA in conjunction with 3D mapping may offer the opportunity for effective ablation of atrial arrhythmias beyond AF.