Compliance of the digital artery is decreased in patients with essential hypertension.
The compliance of the arterial vascular system is decreased in hypertensive subjects. On the other hand, the vessel wall properties such as compliance depend on blood pressure (BP). The aim of the present study was to determine the compliance of the digital arteries and to test the hypothesis that decreased compliance is either caused by a downward shift of the compliance-pressure relation or, alternatively, by a change in the compliance-pressure relation itself. We used impedance plethysmography and a finger BP measuring device to determine beat-to-beat the pressure-pulse amplitude (delta P), the volume-pulse amplitude (delta V) and the compliance from digital arteries of 10 hypertensive patients and 10 similarly aged normal subjects. The mean local blood pressure (MLBP) in the digital arteries was changed by vertically varying the position of the right hand in relation to the heart. The compliance of the digital arteries in hypertensive patients (2.76 microliters/mm Hg per 100 ml tissue) is significantly (P < 0.05) decreased compared with that in normal subjects (4.03 microliters/mm Hg per 100 ml tissue). A reduction of MLBP by 50 mm Hg leads to an increase of compliance in normotensive subjects from 4.03 to 12.68 microliters/mm Hg per 100 ml tissue but in hypertensive patients only from 2.76 to 6.16 microliters/mm Hg per 100 ml tissue. The slope of the curve in the low pressure range was also markedly decreased in hypertensive patients compared with controls. We conclude, that the compliance-pressure relation is not merely shifted but also extensively alterated in hypertensive patients.
Department of Physiology and Pathophysiology, Technical University of Dresden, Germany.
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RP
Bochmann
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U
Reuter
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A
List
M
M
Grundig
V
V
Sinz
D000328:Adult; D001795:Blood Pressure Determination / Q000295:instrumentation; D003187:Compliance; D017097:Electric Impedance; D005385:Fingers / Q000098:blood supply*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010991:Plethysmography