Crux of the heart

The crux of the heart (Crux cordis) is the anatomical point on the inferior surface of the heart where the atrioventricular groove (coronary sulcus) and the posterior interventricular sulcus intersect. This region is located near the junction of the interatrial and interventricular septa, and is found on the right side of the diaphragmatic surface, close to the base of the heart.

At the crux, several important structures converge:

• The right coronary artery (RCA) typically gives off the posterior descending artery (PDA) at or near the crux in right-dominant circulation, which is the most common pattern. In left or balanced dominance, the left circumflex or both arteries may contribute to the supply in this region.

• The coronary sinus enters the right atrium near the crux.

• The membranous septum and the atrioventricular node are located nearby, making this area clinically significant for conduction system interventions and for understanding the risk of heart block during procedures.