Ethanol infusion in the vein of Marshall: Adjunctive effects during ablation of atrial fibrillation

BackgroundThe vein of Marshall (VOM) is a left atrial (LA) vein that contains autonomic innervation and triggers of AF. Its location coincides with areas usually ablated during pulmonary vein (PV) antral isolation (PVAI).ObjectiveThis study sought to delineate the safety and ablative effects of ethanol infusion in the VOM during catheter ablation of atrial fibrillation (AF).MethodsPatients undergoing PVAI (n = 14) gave consent for adjunctive VOM ethanol infusion. In 10 of 14 patients, the VOM was cannulated with an angioplasty wire and balloon. Echocardiographic contrast was injected in the VOM under echocardiographic monitoring. Two infusions of 100% ethanol (1 ml each) were delivered via the angioplasty balloon in the VOM. LA bipolar voltage maps were created before and after ethanol infusion. Radiofrequency ablation times required to isolate each PV and other procedural data were compared with those of 10 age-, sex-, AF type– and LA size–matched control subjects undergoing conventional PVAI.ResultsThe VOM communicated with underlying myocardium, as shown by echocardiographic contrast passage into the LA. There were no acute complications related to VOM ethanol infusion, which led to the creation of a low-voltage area in the LA measuring 10.6 ± 7.6 cm2 and isolation of the left inferior PV in 4 of 10 patients. Radiofrequency ablation time required to achieve isolation of the left inferior PV was reduced (2.2 ± 4 min vs. 11.4 ± 10.3 min in control subjects, P <.05).ConclusionVOM ethanol infusion is safe in humans, decreases radiofrequency ablation time in the left inferior PV, and may have a role as an adjunct to PVAI.