The circumflex artery, fully titled as the circumflex branch of the left coronary artery, is an artery that branches off from the left coronary artery to supply portions of the heart with oxygenated blood. The circumflex artery itself divides into smaller arterial systems. The areas of the heart it supplies can vary across people, though it always provides part of the left ventricle and the papillary muscle with blood. In less than half of people, it may also supply blood to the sinoatrial nodal artery. With anomalous coronary arteries, the circumflex artery or others may be deformed at birth. Such a defect can present a great danger to the child (especially if taking part in aerobic sports) as it can increase risk for heart failure. Medication to strengthen, or surgery to repair the artery may be recommended depending on the severity of the case.