Comparison of arterial occlusion and ischaemic exercise for the study of vasodilatation in the human calf.
1. Calf blood flow was measured by venous occlusion plethysmography to compare two stimuli for eliciting maximal calf vascular conductance: (i) 10 min of arterial occlusion and (ii) isolated exhaustive calf exercise with ischaemic occlusion. The subjects were semi-supine with the calf in position for immediate blood flow measurements after release of the occluding cuff. Three groups of subjects were studied: young [35 years (SD 9, n = 9)], old [57 years (SD 5, n = 10)] and patients with congestive heart failure [63 years (SD 7, n = 7)]. 2. Occlusion and ischaemic exercise were equally effective in producing maximal calf vascular conductance in each of the subject groups. Maximal calf vascular conductance (ml min-1 100 ml-1 mmHg-1) was equivalent in the young [ischaemic exercise 0.54 (SEM 0.03), occlusion 0.54 (SEM 0.05)] and old [ischaemic exercise 0.47 (SEM 0.05), occlusion 0.48 (SEM 0.04)] subjects. However, patients with congestive heart failure exhibited significantly reduced maximal calf vascular conductance [ischaemic exercise 0.20 (SEM 0.02), occlusion 0.20 (SEM 0.01)]. 3. Analysis of the curves, generated by plotting serial calf vascular conductance values obtained immediately and every 15 s after occlusion cuff release for 165 s, revealed differences in the pattern of vasodilatation after occlusion and ischaemic exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
Rueckert
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PA
Department of Medicine, University of Wisconsin Medical School, Madison 53792-3248, USA.
Hanson
P
P
D000328:Adult; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D010991:Plethysmography; D012039:Regional Blood Flow / Q000502:physiology; D014655:Vascular Resistance / Q000502:physiology; D014664:Vasodilation