Computerized evaluation of the peripheral blood flow during maximal vasodilatation in humans using venous occlusion plethysmography
- Resource Type
- Authors
- J. Inacio; I. Gretzer; A. Olsson
- Source
- Clinical Physiology. 15:131-141
- Subject
- Adult
Male
Brachial Artery
Physiology
Vasodilation
Venous occlusion plethysmography
Venous stasis
Reference Values
Occlusion
Image Processing, Computer-Assisted
medicine
Humans
Plethysmograph
Derivation
Vein
business.industry
Ultrasonography, Doppler
General Medicine
Blood flow
Middle Aged
medicine.disease
Plethysmography
Forearm
medicine.anatomical_structure
Anesthesia
Hypertension
Female
Rheology
business
Blood Flow Velocity
- Language
- ISSN
- 1365-2281
0144-5979
Summary. Forearm blood flow was studied with venous occlusion plethysmography after ischaemic exercise in 10 healthy volunteers and 10 hypertensive patients. The peak blood flow was calculated by three methods: the manual conventional graphic technique and by fitting of a tangent to the inflow curve with the help of a computer. In addition a computer-aided derivation of an exponential curve adapted to the initial part of the inflow curve was used for the calculation of the maximal blood flow. With the two tangential techniques the peak mean blood flow values did not differ significantly and were 58 ml min-1 100 ml-1 tissue while the exponential derivation procedure gave in both groups about 40% higher maximal flow values. The effect of venous occlusion on the linear velocity of the brachial arterial blood flow blood was studied with Ultrasound Doppler Flowmetry. The maximal flow velocity after ischaemic exercise decreased by about 18% during 50 mmHg venous occlusion; the influence of the venous stasis was least during the first heart beats after the onset of the venous occlusion. The effect of the venous stasis was similar but less pronounced in the hypertensive patients. In conclusion, forearm blood flow during maximal vasodilatation is reduced by venous occlusion and the best estimate of the flow is obtained from the earliest part of the venous occlusion inflow curve, as indicated by the use of the computer-aided exponential derivation technique.