Acute Nonsustained Mitral Isthmus Block Obtained With Sphere-9 Lattice-Tip Catheter Completed With Vein of Marshall Ethanol Infusion.

Background: Achieving a durable mitral line block using radiofrequency as a part of an anatomical approach for ablation in patients with persistent atrial fibrillation or for treating peri-mitral flutter has always been challenging due to the complex anatomy of the mitral isthmus. Epicardial ablation via the coronary sinus and the vein of Marshall has been proposed to help create durable lesions. Recently, a novel lattice-tip catheter using pulsed field ablation has shown promising results for creating mitral lines, despite limited data.

Methods And Results: We present a case demonstrating the recovery of connection through the mitral isthmus after a waiting period, despite initial clear isolation achieved by creating an endocardial linear lesion. This necessitated further epicardial lesions, performed via ethanol infusion into the vein of Marshall, due to the presence of a coronary sinus CRT lead in this patient.

Conclusion: Despite the high rates of acute mitral line block with PFA the rate of recurrence might be significant. Considering its novelty, our experience with point-by-point PFA is more limited. The present case report highlights the risk of delayed reconnection treated with EI-VOM. Further studies are warranted to explore additional outcomes and recurrence patterns among these patients.