Background: The vein of Marshall (VOM) may act as an epicardial bridge to the Mitral isthmus (MI).
Objective: The aim of this study was to investigate the efficacy of adjunctive VOM Ethanol infusion (VOM-Et) for achieving MI block (characterized by bidirectional block across the line).
Methods: The index procedure of 144 patients in whom adjunctive VOM-Et was used for achieving MI block (VOM group, 65±10 years old) was compared to a series of 142 patients with MI ablation using RF only (RF group, 60±10 years old). Success rate in MI block, RF duration required for achieving MI block and reconnection of MI at redo procedures were compared.
Results: In the VOM group, MI block was achieved in 142/144 patients, while in the RF group, it was achieved in 88/142 patients (98.6 % vs. 62%; p < 0.001). RF duration to achieve MI block was significantly shorter in the VOM group compared to the RF group (5.9±5.1 min vs. 18.7±9.2 min, respectively; p < 0.001). In the repeat procedure, 13/26 patients in the VOM group had MI reconnection vs 37/49 patients in the RF group (50% vs. 76%; p = 0.04). RF duration to re-achieve MI block was shorter in the VOM group (2.0 ± 4.6 min vs. 8.0 ± 7.8 min, respectively; p < 0.001).
Conclusion: The VOM-Et dramatically facilitates the achievement of more durable MI block compared to RF only.