fig55

Figure 55. (A) Echo-Doppler studies from a suprasternal notch projection demonstrating laminar flow pattern in the descending aorta (DAo) in a premature baby with a small patent ductus arteriosus (not shown). (B) A continuous wave Doppler trace displays typical systolic flow (SF) (*) and normal anterograde flow in diastole (ADF) in the DAo. Note that the diastolic flow is visualized below the reference line. Reproduced from Ref.^[36].