Pressure contour analysis in the assessment of arterial stenosis

Femoral artery pressure contour can be measured directly by percutaneous needle puncture and may be a useful indicator of proximal vessel stenosis. Pressure waveform in 53 limbs was compared with radiological appearance of the aorto-iliac segment. Forty-one limbs were graded angiographically as normal and 12 as stenosed. Pressure contour was studied at rest and after intra-arterial injection of papaverine. The following parameters were examined: 1. systolic pressure at rest 2. systolic pressure after papaverine 3. per cent reduction of systolic pressure after papaverine 4. pulse pressure at rest 5. pulse pressure after papaverine 6. per cent reduction in pulse pressure after papaverine 7. maximal gradient (dp/dt) at rest 8. maximal gradient after papaverine: p less than 0.001 (Figure 5b) 9. (formula; see text) A significant difference between the angiographic normal and stenotic groups was found in the values of all parameters. p less than 0.001 for 1 to 8 inclusive; p less than 0.05 for 9. Good discrimination between groups was achieved only by 3, 6 and 8. Three produced the best discrimination: systolic pressure reduction after papaverine greater than or equal to 14 per cent indicating stenosis (1 in 12 false negative) and less than 14 per cent indicating no stenosis (no false positive).