2.2 | Vein of Marshall ethanol infusion (VOM-EI)
The technique of VOM-EI has been described elsewhere.10 In brief, we cannulated the CS with an 8.5 Fr steerable sheath (Agilis NXT, Abbott Inc, St. Paul, MN) and placed a 6‐Fr left internal mammary artery (LIMA) guiding catheter into the great cardiac vein. In a right anterior oblique view, we performed angiography to localize the ostium of the VOM. If a suitable VOM was present, we positioned on an over-the-wire percutaneous coronary angioplasty balloon (Emerge 1.5-2.5 mm x 8 mm; Boston Scientific) into the proximal VOM advanced over a preloaded coronary guide-wire (Sion Blue, Asahi Intecc USA, Inc, Santa Ana, CA). After balloon inflation, we removed the guidewire and obtained a selective VOM angiography by injecting contrast through the wire port of the balloon. After ensuring proximal balloon occlusion and adequate VOM angiography, we slowly injected 96% ethanol into the VOM over 1-2 minutes. During VOM-EI, we monitored the cycle length of peri-mitral flutter in patients with ongoing tachycardia. In case of sinus rhythm, we paced the left atrium from the left atrial appendage and measured the delay on the decapolar catheter placed over the mitral isthmus via the great cardiac vein. After VOM-EI, we performed selective VOM angiography to document chemical ablation of the VOM.
The following day, we recorded a 12-lead-ECG in all patients and performed transthoracic echocardiography to rule out pericardial effusion. We obtained cardiac biomarkers the evening of the procedure and the following morning.