ENHANCING CLINICAL OUTCOMES IN ATRIAL FIBRILLATION ABLATION: EVALUATION OF HIGH- AND VERY HIGH-POWER SHORT-DURATION TECHNIQUES AND THE ROLE OF LOCAL IMPEDANCE DROP IN GUIDING EFFECTIVE PULMONARY VEIN ISOLATION
Salló Zoltán
Cardiovascular Medicine and Research Division
Dr. Merkely Béla
SE Városmajori Klinikák Tanterme
2026-07-31 16:00:00
Cardiovascular Disorders: Physiology and Medicine of Ischaemic Circulatory Diseases
Dr. Merkely Béla
Dr. Szegedi Nándor
Dr. Bencsik Gábor
Dr. Bári Zsolt
Dr. Járai Zoltán Miklós
Dr. Riba Ádám
Dr. Sax Balázs
The aim of this doctoral thesis was to improve the efficacy, safety, and reproducibility of RF catheter ablation for AF by addressing two key determinants of lesion formation: the mode of energy delivery and the real-time assessment of tissue response.
In the first part, evaluation of characteristics of PVI procedures performed with different RF energy settings including the presence of FPI, and the long-term success of the ablation was assesed. Between 2019 and 2021 data of 156 patients were prospectively collected who underwent their first PVI due to paroxysmal or persistent AF. The procedures were performed using three different energy settings: 30W (LPLD ablation, n=53), 50W (HPSD ablation, n=50), and 90W (vHPSD ablation, n=53). The results demonstrated that increasing RF power to HPSD and vHPSD settings significantly reduced procedural and RF delivery times while increasing FPI and improving mid-term arrhythmia-free survival compared with conventional LPLD ablation. These findings demonstrate that accelerated workflows can enhance, rather than compromise lesion durability when lesion continuity and catheter stability are maintained.
In parallel, this work provides clinical validation of LI monitoring as a direct physiological marker of effective lesion formation. The role of LI drop in tissue lesion formation during PVI using a novel ablation catheter in patients with paroxysmal AF was investigated. Procedures followed a standardized protocol, and lesion characteristics were analyzed. The findings showed that LI drop reliably indicates successful lesion formation. This work was the first to clinically define threshold values for effective ablation with this technology: >21.80 Ohms on the anterior and >18.30 Ohms on the posterior wall of the PVs. Applying these targets reduced lesion formation time without significant differences in CF or force-time integral between successful and unsuccessful lesions.
