The atria of the heart are separated from the ventricles by the coronary sulcus (also called coronary groove, auriculoventricular groove, atrioventricular groove, AV groove). The structure contains the trunks of the nutrient vessels of the heart, and is deficient in front, where it is crossed by the root of the pulmonary trunk. On the posterior surface of the heart, the coronary sulcus contains the coronary sinus.
There are two coronary sulci in the heart including left and right coronary sulci.
The left coronary sulcus originates posterior to the pulmonary trunk, and travels inferiorly separating the left atrium and left ventricle. The location of the left coronary sulcus is marked by the circumflex branch of left coronary artery and coronary sinus.
Similarly, the right coronary sulcus begins anteriorly and superiorly on the sternocostal surface of the heart. Its position is marked by the location of the right coronary artery and small cardiac vein. The right coronary sulcus separates the right atrium and its auricle from the right ventricle inferiorly. The right coronary sulcus then passes inferiorly onto the diaphragmatic surface of the heart and traverses to the left.