sentences:  In contrast, the atrioventricular nodal branch, that is the artery that brings blood to the atrioventricular node, depends on coronary artery dominance.The sinoatrial node surrounds the sinoatrial artery, which can run centrally (in 70% of individuals) or off center within the node.A left S-shaped sinoatrial artery, originating from the proximal left circumflex or LCx artery, has been described as a common variant in approximately 10% of human hearts.