Deceleration vs. acceleration: a haemodynamic parameter in the assessment of vascular reactivity. A preliminary study.
The parameter deceleration vs. acceleration (dc/ac) as derived from the instantaneous peak velocity is obtained by dividing the descending and ascending slopes of plotted velocity curves. Blood velocities were recorded with a specially designed continuous-wave ultrasonic Doppler unit which provides: the instantaneous peak velocity, the instantaneous mean velocity, the acceleration, and an indication of volume flow. A physical meaning to the dc/ac parameter is given through an analysis, based on an electrical model, of a small portion of an artery. This gives a simple relationship which only takes account of the assumed vascular resistances. Measurements were performed in 67 male subjects; 39 were normotensive control subjects and 28 had established moderate hypertension. In both groups there was an increase of dc/ac in passing from the supine to the erect position, the increase being more accentuated by hypertension. The variation of dc/ac with age was significantly different in both groups. The results suggest that this parameter is a sensitive indicator of variations in vascular reactivity and as an indicator of structural changes in the arterial wall.
Sainz
A
A
Department of Basic Medical Sciences, Universitat de LLeida, Spain.
Cabau
J
J
Roberts
V C
VC
D000293:Adolescent; D000328:Adult; D001698:Biomedical Engineering; D055592:Biophysical Phenomena; D001703:Biophysics; D001783:Blood Flow Velocity / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000502:physiology; D014463:Ultrasonography; D014655:Vascular Resistance / Q000502:physiology