Examples of antegrade coronary artery flow in the proximal and middle segments of Cx. (A) In modified parasternal short-axis view focusing on the area adjacent to the left sinus of Valsalva the proximal circumflex coronary artery (pCx) is seen leaving the left main coronary artery (LM). (B and C) In modified parasternal short-axis views the proximal and middle segments of the circumflex coronary artery (Cx) are found passing caudally in the lateral atrioventricular sulcus. (D) From parasternal modified long-axis view focusing on the lateral atrioventricular sulcus the middle Cx (mCx) is seen traversing caudally. Ao = aortic root/valve; LA = left atrium; LAD = left anterior descending coronary artery; LV = left ventricle; mLAD = middle segment of LAD; PA = pulmonary artery; pLAD = proximal segment of LAD; RV = right ventricle.