PhD Scientific Days 2022

Budapest, 6-7 July 2022

Characteristics of very high-power, short-duration radiofrequency applications

Gábor Orbán1, Zoltán Salló1, Péter Perge1, Pál Ábrahám1, Katalin Piros1, Klaudia V. Nagy1, István Osztheimer1, Béla Merkely1, László Gellér1 and Nándor Szegedi1
1Heart and Vascular Center, Faculty of Medicine, Semmelweis University, Hungary

Text of the abstract

Introduction: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Pulmonary vein isolation (PVI) is the cornerstone of rhythm-control therapy for AF. Although there have been numerous recent advancements, the recurrence of AF is still a problem. Therefore, further technological development is inevitable. The very high-power, short-duration (vHPSD) radiofrequency (RF) ablation is a novel technology that favors resistive heating while decreasing the role of conductive heating.

Aims: Our study aimed to evaluate the correlations between contact force (CF), power, impedance drop (ID), and temperature; and to assess their role in lesion formation with the vHPSD technique.

Methods: Consecutive patients, who underwent initial point-by-point RF catheter ablation
for AF at the Heart and Vascular Centre of Semmelweis University, Budapest, Hungary, between March and November of 2021, were enrolled in the study. The vHPSD ablation was performed applying 90 W for 4 s with an 8 ml/min irrigation rate.

Results: Data from 85 patients (median age 65 [59-71] years, 34% female) were collected. The median procedure time, left atrial dwelling time, and fluoroscopy time were 70 (60-90) min, 49 (42-58) min, and 7 (5-11) min, respectively. The median RF time was 312 (237-365) sec. No steam pop nor major complications occurred. A total of 6551 vHPSD RF points were analyzed. The median of CF, maximum temperature, and ID were 24 (17-35) g, 47.6 (45.1-50.4) °C, and 8 (6-10) Ohms, respectively. CF correlated significantly with ID (p<0.0001) and with the maximum temperature (p<0.0001). The maximum temperature and ID also showed a significant correlation (p<0.0001). A CF of 5 grams and above was associated with a significantly higher temperature compared to those lesions with a CF below 5 grams (p<0.0001).

Conclusion: The maximum temperature, CF, and ID significantly correlate with each other during vHPSD applications. A CF greater than or equal to 5 grams leads to optimal tissue heating, thus is more likely to result in good lesion formation.

National Research, Development and Innovation Office of Hungary (NKFIA; NVKP_16-1-2016-0017 National Heart Program).
Thematic Excellence Programme (Tématerületi Kiválósági Program, 2020-4.1.1.-TKP2020) of the Ministry for Innovation and Technology in Hungary.