What does flow reversal in diastole indicate?

Flow reversal in diastole indicates high resistance distally. This phenomenon can occur in vascular systems where the resistance to blood flow is significantly elevated, such as in certain peripheral vascular diseases or in cases where there are distal vascular beds that are constricted or inadequately supplied with blood.

When flow is measured with Doppler ultrasound, a high-resistant vascular bed can present with a characteristic diastolic flow reversal, meaning that instead of continuous forward flow during diastole, there is an observed backflow. This can signal issues such as arterial narrowing or distal vasoconstriction which increase the resistance downstream, and thus alter the normal flow pattern.

It is essential to recognize that this flow reversal serves as a critical diagnostic indicator, guiding further investigation and management of potential vascular complications.