Recurrent Perimitral Flutter due to Vein of Marshall Epicardial Connections Bypassing the Mitral Isthmus

Abstract

A 68-year-old man with hypertension, dyslipidemia, obstructive sleep apnea, chronic obstructive pulmonary disease, sick sinus syndrome status post dual chamber pacemaker, and a history of 2 pulmonary vein isolation ablations for persistent atrial fibrillation was evaluated in our institution for recurrent atrial flutter.He underwent a complete electrophysiology study. A duodecapolar catheter was used, so that the distal 10 poles were inside the coronary sinus (CS) and the proximal were in the right atrium. The underlying rhythm was atrial flutter with a cycle length of 350 ms and ostial-to-distal activations in the CS. Responses to entrainment were consistent with a left atrial origin. After a trans-septal puncture, a 3-dimensional map of the left atrium was performed using the NavX system (St Jude Medical, St Paul, MN) and a circular duodecapolar catheter, which was consistent with counterclockwise perimitral flutter (PMF). However, the entire cycle length was not present in the mitral annulus ( Figure A To ascertain the role of the vein of Marshall (VOM) in providing with epicardial connections bypassing the endocardial mitral isthmus scar, we cannulated the VOM via the CS. A sheath was inserted in the CS through the right internal jugular vein. A LIMA (left internal mammary artery) angioplasty guide catheter was inserted in the CS with its tip facing posteriorly and superiorly in the right anterior oblique projection ( Figure E). Contrast injection identified the VOM, which was subsequently cannulated with a 0.014″ angioplasty wire and 2×6 mm angioplasty balloon (Medtronic, Minneapolis, MN; Figure E and F). VOM signals were obtained by connecting the angioplasty wire in a unipolar fashion using alligator clips with the indifferent electrode clamped to the skin. By slightly exposing the wire beyond the balloon, only the exposed wire tip (≈3 mm) would serve as an electrode, which could be located by the NavX system, and from which unipolar signals could be sequentially recorded at different depths of the VOM. Local activation times from different levels of the VOM were added to the NavX map ( Figure C and D) and were shown to complete the reentrant activation sequence with the portion of the cycle length that was missing in the endocardial map.Up to 4 injections of 98% ethanol were injected via the angioplasty balloon at different depths of the VOM. The first injection led to termination of the PMF (Figure G and H). Bidirectional perimitral block was subsequently proven by differential pacing. No radiofrequency ablation was required. DiscussionPMF is a macroreentrant tachycardia that typically occurs after left atrial ablation for atrial fibrillation. PMF is commonly treated by ablation in the so-called mitral isthmus, although this has been consistently reported as suboptimal. Failures can occur due to poor catheter contact, motion, or the thickness of the lateral ridge of the left atrium, as well as epicardial cooling of CS or VOM flow.1,2 It has also been hypothesized to occur due to remaining epicardial co...

Ethanol infusion for Marshall bundle epicardial connections in Marshall bundle‐related atrial tachycardias following atrial fibrillation ablation: The accessibility and success rate of ethanol infusion by using a femoral approach

“…The vein or ligament of Marshall, is an anatomical structure related to atrial tachyarrhythmia . The Marshall bundle is reported to be involved with complex atrial tachycardia (AT) by bridging endocardial activation . Ethanol infusion is one strategy to treat Marshall bundle‐related atrial tachycardia (MB‐AT) .…”

“…The Marshall bundle is reported to be involved with complex atrial tachycardia (AT) by bridging endocardial activation . Ethanol infusion is one strategy to treat Marshall bundle‐related atrial tachycardia (MB‐AT) . Previous reports have suggested that the accessibility of the vein of Marshall (VOM) by an angiographic catheter is limited .…”

Isolation of the conduction between the Marshall bundle and distal coronary sinus and the entire coronary sinus for an atrial tachycardia after catheter ablation of atrial fibrillation

“…Although the relationship between the VOM and genesis of AF have been previously reported,3, 4 there have been reports of catheter ablation of recurrent ATs via the VOM after AF ablation in a few cases 5, 6, 7, 8. In many of the previous reports, it could be confirmed that the VOM was the origin of the arrhythmia or a part of the reentry circuit, by inserting a thin electrode catheter into the Marshall vein 6, 7.…”

“…This ablation method would be less invasive than any other method, and would therefore be useful. We also believed ablation at the anterior ridge of the PV or an ethanol injection would be useful 8 . However, in such a case with a thin and short VOM, we recommend that an ablation in a branch of the VOM from the CS should be preferentially selected for the ablation of an AT via the VOM.…”

Not so typical: The role of epicardial connections in typical flutter refractory to block across the cavotricuspid isthmus

“…The vein of Marshall has been postulated to harbor epicardial connections between the coronary sinus (CS) and the left atrium (LA), sustaining peri‐mitral flutters refractory to endocardial ablation 2,3 . Conduction across the intercaval bundle, which connects the right atrium to the right superior pulmonary vein, has been reported to render isolation of the RSPV challenging requiring ablation at the carina or from the RA 4,5 .…”