Which statement best describes diastolic flow reversal?

Which statement best describes diastolic flow reversal?

• A. It is always an abnormal finding
• B. It is seen in and proximal to high-resistance vessels
• C. It is never seen in vessels supplying low-resistance beds
• D. It is enhanced by body heating

Answer: (B)

Diastolic flow reversal reflects the influence of downstream impedance on the arterial waveform. When a vessel feeds a high-resistance bed, the energy from systole encounters a strong downstream load, causing wave reflections that travel back toward the probe and can produce retrograde flow during diastole. This reversed diastolic flow can be seen not only at the site of the high-resistance bed but also in the artery proximal to it, where reflected waves re-enter the flow toward the heart. Because high-resistance beds commonly produce this diastolic reversal, it isn’t necessarily abnormal. By contrast, vessels supplying low-resistance beds tend to maintain forward diastolic flow, and heating—by lowering peripheral resistance—would more often lessen any diastolic reversal rather than enhance it.

Diastolic flow reversal reflects the influence of downstream impedance on the arterial waveform. When a vessel feeds a high-resistance bed, the energy from systole encounters a strong downstream load, causing wave reflections that travel back toward the probe and can produce retrograde flow during diastole. This reversed diastolic flow can be seen not only at the site of the high-resistance bed but also in the artery proximal to it, where reflected waves re-enter the flow toward the heart. Because high-resistance beds commonly produce this diastolic reversal, it isn’t necessarily abnormal. By contrast, vessels supplying low-resistance beds tend to maintain forward diastolic flow, and heating—by lowering peripheral resistance—would more often lessen any diastolic reversal rather than enhance it.