Common femoral artery Doppler wave-forms: a comparison of three methods of objective analysis with direct pressure measurements.

Doppler maximum frequency wave-forms recorded from the femoral arteries of 50 patients with arterial disease have been submitted to three methods of objective analysis in an attempt to quantify the degree of proximal narrowing. The methods were compared with direct femoral artery pressure measurements at rest and during hyperaemia. There was marked overlap between the results of both pulsatility index and Laplace transform damping when compared with pressure assessment. Principal component analysis, however, produced significantly better agreement than Laplace transform damping (chi 2 = 5.8, P less than 0.02) and in addition was found to be sensitive to the presence or absence of disease in the superficial femoral artery. Principal component analysis appears to be the most powerful method of Doppler wave-form analysis so far described and may have a place in the non-invasive assessment of the aorto-iliac segment.