Blood Flow in the Calf During and After Exercise: Measurements with Doppler Ultrasound and Venous Occlusion Plethysmography in Healthy Subjects and in Patients with Arterial Occlusive Disease

We applied near-infrared spectroscopy (NIRS) for the simultaneous measurement of forearm blood flow (FBF) and oxygen consumption (VO2) in the human by inducing a 50-mmHg venous occlusion. Eleven healthy subjects were studied both at rest and after hand exercise during vascular occlusion. FBF was also measured by strain-gauge plethysmography. FBF measured by NIRS was 1.9 +/- 0.8 ml.100 ml-1.min-1 at rest and 8.2 +/- 2.9 ml.100 ml-1.min-1 after hand exercise. These values showed a correlation (r = 0.94) with those obtained by the plethysmography. VO2 values were 4.6 +/- 1.3 microM O2 x 100 ml-1.min-1 at rest and 24.9 +/- 11.2 microM O2 x 100 ml-1.min-1 after hand exercise. The scatter of the FBF and VO2 values showed a good correlation between the two variables (r = 0.93). The results demonstrate that NIRS provides the particular advantage of obtaining the contemporary evaluation of blood flow and VO2, allowing correlation of these two variables by a single maneuver without discomfort for the subject.

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Cutaneous microcirculation in patients with peripheral arterial occlusive disease: Comparison of capillary blood circulation in the nail fold of finger and toe

Clinical Hemorheology and Microcirculation ◽

10.3233/ch-209220 ◽

2020 ◽

Vol 76 (2) ◽

pp. 279-285

Author(s):

C. Mrowietz ◽

H. Sievers ◽

G. Pindur ◽

B. Hiebl ◽

F. Jung

Keyword(s):

Peripheral Arterial Occlusive Disease ◽

Healthy Subjects ◽

Maximum Velocity ◽

Arterial Occlusive Disease ◽

Occlusive Disease ◽

Vascular Area ◽

Peripheral Arterial ◽

Stenotic Area ◽

Nailfold Capillaries ◽

Apparently Healthy

In patients with peripheral arterial occlusive disease (PAOD) a restricted circulation in cutaneous microvessels has been reported. In this study the velocity of erythrocytes (very) in finger nailfold capillaries - a vascular area without upstream macroangiopathy - and also in toe nailfold capillaries - a post-stenotic area –was investigated using capillary microscopy in apparently healthy subjects and patients with PAOD. Already in finger nailfold capillaries very of patients with PAOD under resting conditions was significantly lower than in capillaries of healthy subjects. This was also true for the circulation in toe capillaries. In addition, the erythrocyte velocities under resting conditions in the toe capillaries were significantly lower than in the finger capillaries. Similar results were found for the duration and the maximum velocity of postocclusive hyperemia. It is concluded that the resting blood flow in the skin microcirculation is impaired in PAOD patients, both under resting conditions and during postocclusive hyperemia in finger as well in toe nailfold capillaries.

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Parathyroid Hormone's Acute Effect on Vasodilatory Function

Clinical Medicine Insights Endocrinology and Diabetes ◽

10.4137/cmed.s4650 ◽

2010 ◽

Vol 3 ◽

pp. CMED.S4650 ◽

Cited By ~ 2

Author(s):

P. Farahnak ◽

L. Lind ◽

K. Mattala ◽

I-L. Nilsson

Keyword(s):

Cardiovascular Disease ◽

Blood Flow ◽

Healthy Subjects ◽

Forearm Blood Flow ◽

Acute Effect ◽

Venous Occlusion ◽

Arterial Infusion ◽

Resistance Vessels ◽

Vasodilatory Function ◽

Pth Level

Parathyroid hormone (PTH) seems to affect the risk of cardiovascular disease. The aim of the present study was to investigate PTH's acute effect on endothelial vasodilatory function in forearm resistance vessels. Ten healthy subjects underwent forearm venous occlusion plethysmography. We measured forearm blood flow at baseline and at a stable, locally increased PTH level after intra-arterial infusion of metacholine and nitroprusside. The contralateral arm served as a control. Ionized calcium (Ca++) and PTH values were normal in all subjects at baseline (1.26 ± 0.02 mM/L, 3.6 ± 1.2 pM/L). After 30 minutes of PTH infusion, the PTH level increased in the active arm (13.8 ± 4.0 pM/L P < 0.01), while the Ca++ level was unchanged (1.25 ± 0.04; mM/L). Both the PTH and the Ca++ level in the contralateral arm remained unchanged, which indicates no systemic influence. The endothelial-dependent vasodilation was inversely correlated to the Ca++ level at baseline (r = −0.75, P < 0.05) and after PTH infusion (r = −0.68, P < 0.05). The vasodilatory function was not affected during PTH-infusion.

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