Oblique Vein of the Left Atrium

Description

Viewed from the left posterolateral aspect of the heart, the oblique vein of the left atrium (vena obliqua atrii sinistri, vein of Marshall) courses superiorly on the posterior wall of the left atrium, running obliquely between the left atrial appendage region anteriorly and the left pulmonary veins more posteriorly. It typically descends toward and joins the coronary sinus near its left end, adjacent to the atrioventricular (coronary) sulcus. Surrounding epicardial fat, the myocardium of the left atrium and left ventricle, and accompanying coronary vessels on the ventricular surface would be visible in close relation. That small vein matters out of proportion to its caliber because it marks the vestigial left superior vena cava pathway (ligament of Marshall and its vein) and sits along a known arrhythmogenic substrate on the left atrial ridge. In electrophysiology, the Marshall bundle can provide triggers or drivers for atrial fibrillation and perimitral flutter, and ethanol infusion of the vein of Marshall is used as an adjunct to facilitate mitral isthmus block when standard endocardial ablation proves difficult. A useful landmark. Use this asset for teaching left atrial venous anatomy in gross anatomy and cardiovascular modules, for illustrating coronary sinus region relationships in EP and cardiothoracic surgery texts, or for figures discussing vein of Marshall ethanol ablation technique and complications (coronary sinus injury, pericardial effusion). Anatomical accuracy verified by SciePro's Medical Advisory Board.