Pulse wave velocity. A new calculation method.
BACKGROUND
The increase in aortic Pulse Wave Velocity (PWV) is considered a surrogate marker of vascular disease; it can be non-invasively assessed by means of an indirect method calculating the time that the pulse wave takes to travel a definite distance along the vasculature; the distance/time ratio corresponds to the velocity measure. The presentation of a new calculation method is the aim of the present study.


METHODS
A duplex scanner at the common carotid artery, the abdominal aorta at the prebifurcation site and the femoral common artery levels, was performed on 127 out-patients with risk factors, 38 of which were affected by clinical vascular disease, and on 50 healthy subjects (control group). The spectral analysis from these three sites was registered simultaneously with an ECG trace and the interval between the R wave apex and the spectral complex systolic foot was measured. The Transit Time (TT) was calculated by the difference between the values obtained from the proximal and distal measurement sites and PWV dividing the distance between them by the TT (PWV = Distance/TT); statistical significance and intra and inter observer variation coefficient, expressed as mean +/- standard deviation, were calculated by the analysis of variance and Turkey test, the correlation with the major risk factors and the intima-media thickness by the multivariate analysis.


RESULTS
The PWV is increased in the patients group compared to control group (p < 0.001). Multivariate analysis shows a positive correlation with age, hypercholesterolemia, arterial hypertension, diabetes mellitus, intima-media thickness and arterial disease, no correlation was found with the smoking habit. The "patients" group shows an increased PWV in those with atherosclerotic plaques and/or clinical vascular disease compared to non atherosclerotic patients with risk factors (p < 0.001); the intra and inter observer variation coefficient ranged between 4.87 +/- 1.82% and 8.06 +/- 3.16% respectively.


CONCLUSIONS
The proposed PWV measurement method is simple, quick, reproducible and repeatable, it can separate healthy subjects from patients with risk factors, atherosclerotic plaques and clinical vascular disease. Due to the strong correlation with age, normal values in different age groups are necessary before the PWV can be used as a marker of vascular disease.
Mosti
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Centro Studi Città di Lucca.
Iabichella
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ML
Picerni
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D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000502:physiology; D001783:Blood Flow Velocity; D002339:Carotid Arteries / Q000502:physiology; D005260:Female; D005263:Femoral Artery / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011674:Pulse / Q000379:methods*