Acute mitral block: pulse field ablation plus radiofrequency ablation when compared to radiofrequency ablation plus ethanol injection of vein of Marshall.

This retrospective study evaluated two groups: patients receiving RFA for PVI, posterior wall isolation, mitral isthmus, and coronary sinus (CS) ablation with adjunctive VOM ethanol injection (VOM/RFA ALL (N = 53)), and patients receiving PVI with PFA using pentaspline catheter followed by mitral isthmus and CS ablation with RFA (PFA PV + PW/RFA MITRAL (N = 12)). We hypothesized that PFA for pulmonary vein isolation (PVI) facilitates mitral block without adjunctive vein of Marshall (VOM) ethanol injection. Mitral block was achieved in 92.5% of VOM/RFA ALL patients and 83.3% of the PFA PV + PW/RFA MITRAL group (p = 0.31). Endocardial ablation time of the mitral isthmus and RF applications required to achieve a complete block were significantly shorter in the VOM/RFA ALL group (208 s vs 356 s, p < 0.01 and 14.5 vs 24.0, p < 0.01, respectively). Adjunctive VOM ethanol injection appears to still have a role for facilitation of mitral isthmus block in the new era of PFA.