Influence of changes in arterial blood pressure and peripheral arterial resistance on peak systolic velocity ratio

Background: Peak systolic velocity ratio has been described as a parameter to determine the degree of arterial stenosis. But there is very little information about the influence of changes in arterial blood pressure or peripheral arterial resistance during exercise on the peak systolic velocity ratio. Patients and methods: Peak systolic velocity was calculated before and in arterial stenosis in 35 patients with only single stenosis in the femoral or iliacal arteries under 4 different conditions: a) twice under resting conditions as a control, b) increased blood pressure by arm activation but unchanged peripheral vascular resistance, c) increased blood pressure by leg activation with a reduced peripheral vascular resistance by metabolic vasodilatation, d) decreased blood pressure associated with pharmacologically reduced peripheral resistance (10 mg nifedipine). Results: Peak systolic velocity ratio was: a) 5.8 +/- 3.7 and 5.7 +/- 3.3, b) 5.6 +/- 3,6 (the increase in systolic arterial blood pressure was 20 +/- 3 mmHg), c) 6.3 +/- 4.4 (increase in systolic arterial blood pressure was 21 +/- 3 mmHg), d) 5.6 +/- 3,4 (decrease in systolic arterial blood pressure was 18 +/- 8 mmHg) without being significantly different fi om each other: The correlation factors of the peak systolic velocity ratios to the angiographic diameter reduction were between 0.737 and 0.847 Although the mean values suggest that there is no influence from the different exercise tests or nifedipine application on the peak systolic velocity ratio single stenosis demonstrated large reproducible differences. Conclusion: The influence of changes in arterial blood pressure and peripheral resistance on peak systolic velocity ratio appeared small. But a single stenosis showed large increases or decreases of peak systolic velocity ratio possibly due to vasomotion of the prestenotic or stenotic arterial segment.