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 param eter to determine the degree of arterial stenosis. But there is very l ittle information about the influence of changes in arterial blood pre ssure or peripheral arterial resistance during exercise on the peak sy stolic velocity ratio. Patients and methods: Peak systolic velocity wa s calculated before and in arterial stenosis in 35 patients with only single stenosis in the femoral or iliacal arteries under 4 different c onditions: a) twice under resting conditions as a control, b) increase d blood pressure by arm activation but unchanged peripheral vascular r esistance, c) increased blood pressure by leg activation with a reduce d peripheral vascular resistance by metabolic vasodilatation, d) decre ased blood pressure associated with pharmacologically reduced peripher al resistance (10 mg nifedipine). Results: Peak systolic velocity rati o 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 m mHg) without being significantly different fi om each other: The corre lation factors of the peak systolic velocity ratios to the angiographi c diameter reduction were between 0.737 and 0.847 Although the mean va lues suggest that there is no influence from the different exercise te sts or nifedipine application on the peak systolic velocity ratio sing le stenosis demonstrated large reproducible differences. Conclusion: T he influence of changes in arterial blood pressure and peripheral resi stance on peak systolic velocity ratio appeared small. But a single st enosis showed large increases or decreases of peak systolic velocity r atio possibly due to vasomotion of the prestenotic or stenotic arteria l segment.