Figure 1
From: Coronary artery occlusions diagnosed by transthoracic Doppler
Examples of anterograde and retrograde flow in the posterior descending coronary artery. In modified apical long-axis views focusing on the posterior interventricular sulcus, the posterior descending coronary artery (PDA) is imaged by colour Doppler mapping with matching spectral Doppler tracings of blood flow: (A,B) The PDA is seen with anterograde flow. (C,D) The PDA is seen with retrograde flow. Ao = aortic valve and ascending aorta, Ax = apex, D = spectral Doppler tracings of diastolic coronary blood flow, LA = left atrium, LV = left ventricle, RA = right atrium, S = spectral Doppler tracings of systolic coronary blood flow.