Could exercise-induced increase in blood viscosity at high shear rate be entirely explained by hematocrit and plasma viscosity changes?

Aim: We aimed to assess the association of whole blood with thromboembolic milieu in significant mitral stenosis patients. Methodology & results: We included 122 patients and classified patients into two groups as having thrombogenic milieu, thrombogenic milieu (+), otherwise patients without thrombogenic milieu, thrombogenic milieu (-). Whole blood viscosity (WBV) in both shear rates were higher in thrombogenic milieu (+) group comparing with thrombogenic milieu (-). WBV at high shear rate and WBV at low shear rate parameters were moderately correlated with grade of spontaneous echo contrast. Adjusted with other parameters, WBV parameters at both shear rates were associated with presence of thrombogenic milieu. Discussion & conclusion: We found that extrapolated WBV at both shear rates was significantly associated with the thrombogenic milieu in mitral stenosis. This easily available parameter may provide additional perspective about thrombogenic diathesis.

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Evaluation of blood viscosity at high shear rate with a falling ball viscometer

Clinical Hemorheology and Microcirculation ◽

10.3233/ch-1993-13509 ◽

1993 ◽

Vol 13 (5) ◽

pp. 651-659 ◽

Cited By ~ 3

Author(s):

C. Fons ◽

J.F. Brun ◽

I. Supparo ◽

C. Mallard ◽

L. Bardet ◽

...

Keyword(s):

Shear Rate ◽

Blood Viscosity ◽

High Shear Rate ◽

High Shear

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Measuring real-time blood viscosity with a ventricular assist device

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411919838738 ◽

2019 ◽

Vol 233 (5) ◽

pp. 562-569 ◽

Cited By ~ 6

Author(s):

Wataru Hijikata ◽

Takuro Maruyama ◽

Yuki Suzumori ◽

Tadahiko Shinshi

Keyword(s):

Shear Rate ◽

Ventricular Assist Device ◽

Blood Viscosity ◽

Vibrational Excitation ◽

High Shear Rate ◽

Ventricular Assist Devices ◽

High Shear ◽

Assist Device ◽

Ventricular Assist ◽

Artificial Hearts

Ventricular assist devices assist in blood circulation and form a crucial component of artificial hearts. While it is important to measure parameters such as the flow rate, pressure head and viscosity of the blood, implanting additional devices to do such measurements is inadvisable. To this end, we demonstrate the adaptation of a ventricular assist device for the purpose of measuring blood viscosity. Such an approach eliminates the need for additional dedicated viscometers in artificial hearts. In the proposed method, the blood viscosity is measured by applying radial vibrational excitation to the impeller in a ventricular assist device using its magnetic levitation system. During the measurement, blood is exposed to a combination of a low shear rate (≈100/s) generated by the radial vibration of the impeller and a high shear rate (>10,000/s) generated by the impeller’s rotation. The apparent viscosity of blood depends on the shear rate, so we determined which shear rate was the dominant one in the proposed method. The measurement results showed that the viscosity measured by the proposed method was in good agreement with the reference viscosity measured with a high shear rate. The mean absolute deviation in the measurements using the proposed method and those obtained using a concentric cylindrical viscometer at a high shear rate was 0.12 mPa s for four samples of porcine blood, with viscosities ranging from 2.32 to 2.75 mPa s.

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Safety of Five Tuina Manipulations in Rats with Deep Vein Thrombosis

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2021/6897124 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Ying Zhou ◽

Yumo Zhang ◽

Xiaoyan Zhang ◽

Zhuo Chen ◽

Jian Dong ◽

...

Keyword(s):

Deep Vein Thrombosis ◽

Shear Rate ◽

Strain Rate ◽

Rate Ratio ◽

Plasma Viscosity ◽

High Shear Rate ◽

High Shear ◽

Vein Thrombosis ◽

Deep Vein ◽

Low Shear

Objective. To study the effects of five tuina manipulations in rats with deep vein thrombosis (DVT) and to explore how to safely perform tuina in the treatment of thrombotic diseases. Methods. Seventy-two male Sprague-Dawley (SD) rats were randomly divided into the model, pointing manipulation, plucking manipulation, kneading manipulation, pushing manipulation, and pulling manipulation groups (n = 12). DVT model was established by incomplete ligation. The tuina intervention was started on the next day after modeling and applied once a day 10 times by the manipulation simulators. On the 3rd and 10th days after intervention, respectively, the effects of tuina on thrombosis were evaluated based on thrombus elasticity, blood coagulation, fibrinolytic function and blood rheology with the ultrasound elastography, four coagulation tests, enzyme linked immunosorbent assay (ELISA), and hemorheology tests. Results. In the pointing manipulation group, the strain rate ratio, 6-ketoprostaglandin F1α (6-Keto-PGF1α), and high shear rate were decreased, and the thromboxane B2 (TXB2) content was increased ( P < 0.05 ). In the plucking manipulation group, the D-dimer and 6-Keto-PGF1α contents were increased, prothrombin time (PT) was shortened, and activated partial thromboplastin time (APTT) was activated, and the high shear rate and plasma viscosity were decreased ( P < 0.05 ). In the kneading manipulation group, APTT was shortened, and 6-Keto-PGF1α, high shear rate, and plasma viscosity were decreased ( P < 0.05 ). In the pushing manipulation group, the strain rate ratio, low shear rate, and high shear rate were all decreased ( P < 0.05 ). In the pulling manipulation group, both the strain rate ratio and the low shear rate were decreased ( P < 0.05 ). The 6-Keto-PGF1α changes on the 3rd and 10th days after intervention were opposite in the pushing manipulation group and the pulling manipulation group ( P < 0.05 ). Conclusion. The pointing, pushing, and pulling manipulations seem to be safe in the early period of thrombosis, but the risk is likely to be elevated as the treatment course of intervention increases. The plucking and kneading manipulations potentially have certain risks in the treatment of DVT in rats.

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Whole blood viscosity predicts nondipping circadian pattern in essential hypertension

Biomarkers in Medicine ◽

10.2217/bmm-2020-0249 ◽

2020 ◽

Vol 14 (14) ◽

pp. 1307-1316

Author(s):

Abdullah K Dolu ◽

Ahmet Korkmaz ◽

Harun Kundi ◽

Umit Guray

Keyword(s):

Essential Hypertension ◽

Shear Rate ◽

Blood Viscosity ◽

Whole Blood ◽

Blood Pressure Monitoring ◽

High Shear Rate ◽

High Shear ◽

Whole Blood Viscosity ◽

Protein Levels ◽

Low Shear

Aim: We aimed to investigate the association between whole blood viscosity (WBV) and nondipping pattern in patients with essential hypertension. Materials & methods: A total of consecutive 530 patients who had been evaluated by ambulatory blood pressure monitoring were included. WBV was estimated by using hematocrit and plasma total protein levels for both WBV in low shear rate (0.5 s-1) and WBV in high shear rate (208 s-1) according to the de Simone’s formula. Results: In the multivariate analysis, low shear rate and high shear rate of WBV were associated independently with nondipping pattern in patients with essential hypertension. Conclusion: As a simple, inexpensive and noninvasive tool, WBV seems to be a significant predictor of nondipping hypertension.

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