What flow pattern would be expected in the presence of an arteriovenous fistula (AVF)?

What flow pattern would be expected in the presence of an arteriovenous fistula (AVF)?

• A. Decreased diastolic flow and antegrade venous outflow
• B. Increased diastolic flow and retrograde venous outflow
• C. Increased diastolic flow and pulsatile venous outflow
• D. Stable diastolic flow and laminar venous outflow

Answer: (C)

In the presence of an arteriovenous fistula (AVF), an increased diastolic flow and pulsatile venous outflow are the typical characteristics. An AVF is an abnormal connection between an artery and a vein, which allows blood to flow directly from the arterial system into the venous system, bypassing the capillary bed. Because of this connection, the arterial pressure and flow characteristics are transmitted into the venous system, leading to an increase in diastolic flow due to the high pressure coming from the artery. The pulsatile nature arises from the direct influence of the pulsatile arterial blood flow on the venous side, resulting in a distinct pattern that is different from normal venous flow. This altered flow pattern can be important diagnostically, as it highlights the hemodynamic changes that occur with the presence of an AVF, which can be critical for both evaluation and management of vascular conditions.

In the presence of an arteriovenous fistula (AVF), an increased diastolic flow and pulsatile venous outflow are the typical characteristics. An AVF is an abnormal connection between an artery and a vein, which allows blood to flow directly from the arterial system into the venous system, bypassing the capillary bed.

Because of this connection, the arterial pressure and flow characteristics are transmitted into the venous system, leading to an increase in diastolic flow due to the high pressure coming from the artery. The pulsatile nature arises from the direct influence of the pulsatile arterial blood flow on the venous side, resulting in a distinct pattern that is different from normal venous flow.

This altered flow pattern can be important diagnostically, as it highlights the hemodynamic changes that occur with the presence of an AVF, which can be critical for both evaluation and management of vascular conditions.