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Topic

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Left marginal vein

The left marginal vein (LMV) is a prominent tributary of the great cardiac vein, located along the obtuse (left) margin of the heart. It originates from the venous plexus of the left ventricle, particularly draining the lateral wall of the left ventricle, and courses upward toward the atrioventricular groove, where it empties into the great cardiac vein, which ultimately drains into the coronary sinus.

The LMV usually parallels the left marginal artery (a branch of the circumflex artery), creating a venous–arterial pair along the obtuse margin. Its caliber varies among individuals, and it may serve as an access route for cardiac resynchronization therapy (CRT) lead placement during biventricular pacing.

Synonyms

  • LMV

  • Oblique marginal vein

  • Left ventricular marginal vein

Function

  • Drains venous blood from the lateral wall of the left ventricle

  • Contributes to cardiac venous return via the great cardiac vein → coronary sinus → right atrium

  • Provides an important route for interventional cardiology (CRT lead implantation)

  • Plays a role in venous collateral pathways in cases of coronary obstruction

Tributaries

  • Small venous branches from the lateral wall of the left ventricle

  • Frequently interconnected with neighboring cardiac veins, forming venous anastomoses

MRI Appearance

T1-weighted images:

  • LMV lumen appears as a signal void (black) due to venous blood flow

  • Surrounded by epicardial fat, providing contrast for localization

T2-weighted images:

  • Lumen remains a signal void

  • Adjacent myocardium appears intermediate signal; edema or infarction in LMV territory appears hyperintense

STIR (Short Tau Inversion Recovery):

  • Suppresses fat signal, improving visualization of venous margins and adjacent myocardium

  • Hyperintense signal in lateral LV wall indicates edema or infarction

T1 Post-Contrast (Gadolinium-enhanced):

  • LMV enhances brightly and homogeneously after gadolinium administration

  • Improves delineation of LMV course, caliber, and patency

  • Late gadolinium enhancement in adjacent myocardium reveals scar tissue or fibrosis in LMV drainage territory

MRA (Magnetic Resonance Angiography):

  • Contrast-enhanced MRA depicts LMV course and connection to the great cardiac vein

  • Useful for venous mapping before CRT lead placement or venous interventions

CT Appearance

Non-contrast CT:

  • LMV is difficult to identify without contrast; appears as a small soft tissue tubular structure in epicardial fat along the obtuse margin

CT Coronary Venography (contrast-enhanced):

  • Clearly demonstrates LMV as a contrast-filled vessel along the left ventricular margin

  • Shows drainage into the great cardiac vein and its relation to coronary arteries

  • Useful in planning CRT, venous interventions, or evaluation of venous anomalies

  • 3D reconstructions aid in surgical and interventional mapping of coronary venous anatomy

CT image

Left marginal vein anantomy CT axial image -img-00000-00000

CT image

Left marginal vein anantomy CT axial image -img-00000-00000_00001