Final answer:
The distal aorta should have a low resistance waveform, not a high resistance waveform as it supplies organs that need constant blood flow. High resistance waveforms are typical in the peripheral arteries that serve muscles and skin and can exhibit little to no diastolic flow or reversed flow during constriction.
Step-by-step explanation:
The Doppler characteristics of the distal aorta include different flow patterns depending on the resistance in the vascular system. In general, the distal aorta should exhibit a low resistance waveform with continuous forward flow during diastole because this part of the aorta supplies abdominal organs that require a consistent blood supply. A high resistance waveform is more typical of peripheral arteries that supply muscles and skin, which do not need constant blood flow. In these high resistance vessels, you would see little to no diastolic flow, and sometimes a reversed diastolic flow if there is a significant narrowing or blockage.
Therefore, the distal aorta has all the following Doppler characteristics except for 'A) High resistance waveform'. This is because the distal aorta is characterized by low resistance, with a high cardiac output and low peripheral resistance, which allows for a sustained blood flow to satisfy metabolic needs of the organs it supplies.