Which of the following conditions might lead to high diastolic flow in the proximal segment of a CFA?

High diastolic flow in the proximal segment of the common femoral artery (CFA) can occur due to the presence of an arteriovenous (AV) fistula. An AV fistula creates an abnormal connection between an artery and a vein, which allows blood to flow directly from the arterial system to the venous system. This condition often leads to increased blood flow due to the high-pressure arterial blood entering the low-pressure venous system, resulting in a characteristic pattern of altered blood flow dynamics.

In the case of an AV fistula, the diastolic component of the waveform is elevated because there is a sustained flow throughout the cardiac cycle, unlike normal arterial flow that typically shows lower diastolic flow due to complete closure of the arterioles and the resistance they provide. This sustained increase in flow can be attributed to the fact that the blood is being continuously shunted from the artery to the vein, necessitating a compensatory increase in the diastolic flow component.

Other conditions such as stenosis, vascular obstruction, and thrombosis would generally decrease or disrupt normal blood flow characteristics, leading to diminished diastolic flow rather than an increase.

Thus, the presence of an AV fistula is relevant because it creates a