Jennifer MacRae and her colleagues from the University of Calgary, Calgary, Alberta, Canada, reviewed the hemodynamic and cardiovascular consequences of arteriovenous fistulas. Their findings were published in a 2006 paper in Seminars in Dialysis.

MacRae identified three periods when the presence of an AV fistula influences a patient's hemodynamics.

1. Immediate Effects of Creation of an AV Fistula

• Increase in cardiac output (10-20%)
• Increase in sympathetic nervous system activity (increasing contractility)
• Increase in stroke volume and heart rate
• Decrease in peripheral resistance

2. Hemodynamic Changes Within 1 Week of Creation of an AV Fistula

• Increase in circulating blood volume
• Increase in neuro-hormones
• Decrease in plasma renin and aldosterone levels
• Decrease in Systemic vascular resistance and systolic/diastolic blood pressure

3. Consequences of Long-Term AV Fistulas

• Left Ventricular hypertrophy
• High-Output cardiac failure
• Exacerbation of coronary ischemia
• Central vein stenosis

From their analysis, MacRae and her team concluded that:

• A thorough cardiac assessment should be performed in patients with coronary artery disease before placing an AV fistula.
• Regular careful evaluations are necessary in patients with cardiac disease and AV fistulas.
• Patients with a large AV fistula and high flow should be monitored closely.
• Patients with high flow fistulas (flow greater than 2 L/min) and increasing LVEDV are recommended to have a flow reduction procedure on their AVF.
• Patients with preexisting severe ischemic heart disease (class III unstable angina) should avoid an AV fistula placement if the underlying ischemia cannot be treated.