Coronary sulcus

The coronary sulcus (also called the atrioventricular groove) is an external groove that encircles the heart, separating the atria from the ventricles. It contains important vascular structures including the coronary arteries and cardiac veins embedded in epicardial fat.

The coronary sulcus runs circumferentially around the heart at the junction between the atrial and ventricular chambers. The right coronary artery follows the atrioventricular groove between the right atrium and ventricle, while the circumflex branch of the left coronary artery courses posteriorly along the groove between the left atrium and ventricle. Within this sulcus, the great cardiac vein is adjacent to the circumflex artery and the coronary sinus (which receives venous drainage) maintains close relationships with both the right and left coronary arteries.

The coronary sulcus is filled with fibrofatty tissue that provides insulation and separation between the atrial and ventricular myocardium.