BACKGROUND: Radiofrequency (RF) ablation of left ventricular summit arrhythmias (LVSAs) is challenging and may fail due to the anatomical inaccessibility of the substrate. Coronary venous ethanol ablation (CVEA) has been suggested as an alternative ablation strategy for drug- and RF-refractory LVSA. OBJECTIVE: This study compared venous ethanol with or without adjunctive RF (CVEA ± RF) vs optimized RF (ORF) for primary or repeat ablation of LVSA. METHODS: After propensity score matching, 41 of 43 patients treated with CVEA ± RF were compared to 41 of 93 patients who underwent ORF ablation. RESULTS: Patient characteristics were similar for both groups (77% male, median age 65 [56-71] years, median 2 [1-2] previous ablation procedures). The mean pace-match was 97.1 ± 1.7% for venous vs 94.7 ± 3% for conventional mapping (P <
.0002). The earliest presystolic signal was -41 ± 11 ms for venous vs -28 ± 10 ms conventional mapping (P <
.0002). Acute procedural success was 95% vs 83% for CVEA ± RF and ORF respectively (P = .077). Ventricular premature beat burden decreased by 58% after ORF and by 91% following CVEA ± RF (P = .041). In patients with ventricular tachycardia, ventricular tachycardia burden decreased by 96% after CVEA ± RF (P <
.0002), while a 70% reduction was not significant for ORF. After a median follow-up of 24 (12-58) months, 20% of CVEA ± RF patients recurred as compared to 54% following ORF (P = .002). Following ORF ablation, 1 patient developed pericarditis, 1 patient tamponade, and 1 patient atrioventricular block. In the CVEA ± RF group, one patient suffered a vascular access complication. No patients died. CONCLUSION: When venous mapping supports intramural origin, RF-aided venous ethanol ablation is an effective strategy for the treatment of LVSA also when compared to ORF ablation.