Background: The presence of an arteriovenous (AV) fistula creates permanently high cardiac output. This may cause an imbalance between available cardiac oxygen supply in response to greater demand and increased arterial stiffness.
Methods: Surrogate markers of subendocardial perfusion (subendocardial viability ratio [SEVR]) and arterial stiffness (augmentation index [AIx]) can be measured noninvasively by using pulse wave analysis on the radial pulse to obtain central pressures. We prospectively followed up nine patients with chronic renal failure (CRF) undergoing creation of an AV fistula for vascular access at regular intervals over 6 months.
Results: After surgery, blood pressure and heart rate remained unchanged throughout the study period. AIx stayed the same (baseline versus 6 months, 20% +/- 11% versus 22% +/- 15%), but there was a decrease in SEVR immediately after surgery (-9% +/- 5%; P < 0.05) that persisted for at least 3 months (-14% +/- 7%; P < 0.01). At 6 months, SEVR remained below baseline values in all but one patient (mean SEVR at baseline, 166% +/- 22% versus 6 months, 150% +/- 20%; P < 0.05; -9% +/- 7%).
Conclusion: Creation of an AV fistula may directly predispose patients with CRF to a risk for myocardial ischemia caused by an adverse imbalance between subendocardial oxygen supply and increased oxygen demand consequent to a greater cardiac output.
Copyright 2002 by the National Kidney Foundation, Inc.