Small Cardiac Vein

Description

Running in the right atrioventricular (coronary) sulcus, the small cardiac vein (vena cardiaca parva) tracks along the inferior margin of the heart beside the right coronary artery and its marginal branches, draining the superficial myocardium of the right atrium and right ventricle. From an inferior aspect you can follow it from the acute margin proximally toward the crux of the heart, where it typically joins the coronary sinus near its right end. Adjacent surface landmarks include the inferior (diaphragmatic) surface of the right ventricle anteriorly and the right atrium more posteriorly, with the posterior interventricular sulcus lying medial to the vein’s terminal segment. For teaching coronary venous return, this view clarifies a point that is often glossed over: not all venous drainage reaches the right atrium directly. The small cardiac vein is a frequent companion to the right coronary artery in the right AV groove, so it becomes relevant in right-sided coronary artery bypass grafting, tricuspid valve exposure, and procedures that work near the coronary sinus ostium. Variant anatomy matters. The small cardiac vein may be small or absent, and drainage from the right heart can shift toward anterior cardiac veins that empty directly into the right atrium, a pattern that changes what you expect to see during catheter-based coronary sinus cannulation. Use this rendering in gross anatomy and cardiovascular blocks to pair arterial territories with their venous counterparts, and in surgical or interventional diagrams that need a clean inferior roadmap of the coronary sulci. It also fits well in figure plates for cardiology texts discussing coronary sinus anatomy, cardiac resynchronization therapy lead placement, or venous anomalies encountered during electrophysiology cases. Anatomical accuracy verified by SciePro's Medical Advisory Board.