fig50
![Echocardiography: an overview - Part III](https://image.oaes.cc/a251030f-17ae-4989-8cbc-3b1df7232f71/4834.fig.50.jpg)
Figure 50. Doppler interrogation of the descending aorta (DAo) (A) and transverse aortic arch (TAA) (B) showing forward flow in the DAo and retrograde systolic flow in TAA; the latter finding indicates ductal-dependent systemic circulation. Reproduced from Ref.[21].