Middle Cardiac Vein

vena cardiaca media

The middle cardiac vein runs alongside the posterior descending artery in the posterior interventricular groove, draining the inferior left and right ventricles, and enters the coronary sinus at its right posterior aspect. It is the second largest tributary of the coronary sinus after the great cardiac vein. The middle cardiac vein is the target vein for left ventricular pacing lead placement in cardiac resynchronisation therapy for inferior and posterolateral wall resynchronisation.

Region: Chest

Clinical Relevance

Clinical Notes

The middle cardiac vein runs parallel to the posterior descending artery (PDA) and is used as the reference landmark for identifying the PDA during posterior cardiac surgery. In cardiac resynchronisation therapy (CRT), the middle cardiac vein is occasionally used as the target vessel for LV lead placement when lateral or posterolateral veins are absent or inaccessible, though it provides less optimal resynchronisation than lateral veins. The vein also receives the right marginal vein and the small cardiac vein as tributaries near the coronary sinus junction.

Pathology

Common Injuries & Conditions

Middle Cardiac Vein Lead Placement in CRT

When lateral and posterolateral coronary veins are absent, the middle cardiac vein in the posterior interventricular groove provides an alternative LV pacing site for CRT lead placement, though anatomical proximity to the right ventricle means the lead may capture both ventricles, reducing resynchronisation efficacy.