Coronary venous ethanol ablation of refractory left ventricular summit arrhythmias: comparison with radiofrequency ablation

Abstract

Abstract Background Radiofrequency (RF) ablation of ventricular premature beats (VPBs) and ventricular tachycardia (VT) arising from the left ventricular (LV) summit is challenging and may fail due to anatomical inaccessibility of the substrate. Coronary Venous Ethanol Ablation (CVEA) has been suggested as a bailout strategy following failed RF ablation of LV Summit Arrhythmias (LVSA). Comparison with RF ablation strategies are lacking. Purpose To compare CVEA with RF ablation for the treatment of LVSA. Methods Between January and November 2023, 20 patients were treated with CVEA for LVSA. Results were compared to 36 patients that underwent RF ablation for LVSA (Panel A). Endo- and/or epicardial RF ablation was performed based on local signal precocity and pace-mapping. Coronary venogram-guided mapping of coronary sinus side-branches was performed using an angioplasty wire connected to our EP-recording system using a crocodile clamp. The target veins were specifically selected based on early presystolic potentials and confirmed by matching VPB pace-maps. For the treatment, angioplasty balloon(s) measuring 2-2.5×6-8 mm were employed to administer ethanol into the target branch of the coronary sinus. Data are reported as mean ± standard deviation, unless otherwise indicated. P-values are two-tailed. Results (Panel B): Patient characteristics were similar for both groups, except for the number of prior failed ablation procedures (75% males; mean age: 63 ± 13 y; 31 with structural heart disease; mean LVEF 39 ± 9%; VPB burden 25 ± 12%; Number of (NS)VT 72 ± 151; 65% redo in case of CVEA, 28% for RF). Mean pace-match was 97 ± 1% (99.8% max.) for CVEA versus 93 ± 8% (97% max.) for RF ablation (P = 0.002). Earliest presystolic signal was -70 ms (-49 ± 12) for CVEA versus -50 ms (-31 ± 12) for RF (P = 0.0002). Acute success, defined as elimination of VPB/VT was 95% versus 83% for CVEA and RF ablation respectively. VPB burden at Holter was 1 ± 3% 6-8 weeks after CVEA versus 8 ± 10% following RF ablation (P = 0.024). In patients with VT, number of (NS)VT decreased by 90% after CVEA (P = 0.014), while this was not significant for RF ablation. After a median follow-up of 8 months (IQR 2-10), 15% of CVEA patients showed residual non-LV summit ventricular arrhythmia as compared to 39% showing recurrence of LV summit VPB or VT following RF ablation. No patients died. One patient developed tamponade following RF ablation and one patient received PCI in the CVEA group. Conclusion Retrograde coronary venous ethanol ablation is an effective ablation strategy for the treatment of LV summit arrhythmias, also compared to conventional RF ablation.