Optimal catheter-tissue contact value for ablation of ventricular arrythmias originating from the left ventricular papillary muscles

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Good catheter-tissue contact is mandatory to create effective ablation lesions. The minimal contact force (CF) value for successful ablation of arrhythmias originating from the left ventricle (LV) was reported at the 8-10 g level, however, optimal CF values for ablation of arrhythmias arising from papillary muscles (PM) are not known. Purpose To determine optimal CF value for ablation of arrhythmias from LV PM. Methods Twenty-four consecutive patients (mean age 57,9 ± 11,9 years, 16 males) who from May 2017 to June 2020 underwent ablation of premature ventricular complexes (PVC) originating from LV PM were included. The primary endpoints were an acute procedural success (total elimination of PVC) and long-term success (median 27 months). Ablation was performed with the use of the CARTO electro-anatomical system and intracardiac echocardiography (ICE). Results Acute success – complete abolition of PVC, was obtained in 23 (96%) patients. The fluoroscopy time was 3,9 ± 3,5 min and the procedure duration was 114,8 ± 38 min. The mean number of applications was 8,74 ± 6,78 and the mean application time - 518,5 ± 437,25 sec. The mean CF during successful ablations was 3,1 ± 1,5 g, with 3 ± 1,1 g and 3,18 ± 1,8 g for anterolateral and posteromedial PM, respectively (p= 0,809975). The mean CF during one unsuccessful ablation was 3 g. At control Holter ECG, the mean PVC burden in all patients was reduced from 28,36 ± 14,48 % to 2,42 ± 2 %: in the anterolateral PM group from 18 ± 8 % to 2,6 ± 2 % (p= 0,005415) and in the posteromedial PM group - from 34,8 ± 13,7 % to 1,7 ± 1,3 % (p= 0,012694). During long-term follow-up (median 27, IQR 17-34) there was one recurrence among 23 patients who had acutely successful procedures. Conclusion The values of CF for successful ablation of PVC originating from LV PM are lower than those for ablation in other parts of LV. The values slightly exceeding 3 g seem to be sufficient to achieve ablation success.