fig56

Figure 56. Selected video frames in a suprasternal notch projection illustrating retrograde diastolic flow (RDF) in the descending aorta (DAo) in two separate premature infants (A, B), each having a large patent ductus arteriosus (PDA). These babies are expected to have hemodynamically significant PDAs. The low magnitude systolic flow (SF) (*) indicates no sign of descending aortic narrowing. Reproduced from Ref.^[36].