fig61

Figure 61. Doppler recordings from the main (MPA) and left (LPA) pulmonary arteries (A, B) and proximal (C) and distal (D) descending aorta (DAO) illustrating the technique of pulsed Doppler examination in an attempt to detect evidence for obstruction in the LPA and DAO. The flow velocity recordings from the LPA and distal DAO do not show increased Doppler flow velocity suggesting that there is no obstruction at these sites by the device used for occluding the patent ductus arteriosus. Continuous wave Doppler interrogation across the LPA and DAO and color flow imaging were also performed in each case (not shown). Reproduced from Ref.^[40].