[Study of vasomotility in man using plethysmography and flowmetry].
The interpretation of cardiac hemodynamics is indissociable from the study of the peripheral vascular circulation. The latter may now be assessed by non-invasive techniques. Measuring the systemic blood pressure is useful but, in itself, insufficient. The venous sector is usually studied by plethysmographic methods. The commonest of those is occlusion plethysmography either with a mercury gauge or by impedence plethysmography. It is possible to measure venous distensibility, the venous tone. Postural plethysmography improves the study protocol by eliminating the artefact of venous occlusion while respecting the spatial cardiovascular adaptation. The study of the permeability of the capillary walls is a useful complement to venous investigations. Arterial function is approached routinely by qualitative plethysmography which provides little useful information; on the other hand, the measurement of mean arterial blood flow gives a quantitative and physiologically useful parameter. Even better than the mean arterial flow is the pulsatile arterial blood flow which may be measured by pulsed wave Doppler echo, non-invasive electromagnetic flowmetry and NMR flowmetry. Cutaneous blood flow is measured by laser Doppler. It is now possible to measure global pulsatile arterial flow of a segment of limb including its principal and collateral arteries, or the blood flow of a selected artery or even cutaneous blood flow alone. Future trends lie in improving the accuracy of all these measurements of flow and in increasing the possibilities of controlling tissue metabolism. In addition, studies in the microcirculation will become increasingly important: capillary flow, intracapillary distribution, transcapillary exchanges.
Boccalon
H
H
Angéiologie, CHU Rangueil, Toulouse.
D002199:Capillary Permeability; D003187:Compliance; D006801:Humans; D008279:Magnetic Resonance Imaging; D010991:Plethysmography / Q000379:methods*; D011673:Pulsatile Flow; D012039:Regional Blood Flow; D012212:Rheology; D014463:Ultrasonography; D014666:Vasomotor System / Q000502:physiology* / Q000503:physiopathology
Etude de la vasomotricité chez l'homme par pléthysmographie et débitmétrie.