Introduction: Blood viscosity (BV) is an important blood property for determining the hemodynamic status. High BV causes blood stagnation and subsequent thrombotic reactions leading to cerebral infarction. However, clinical application of the measurement of BV is out of fashion due to the stereotype that the measurement results are within expectations with less clinical value.
Hypothesis: Since the importance of BV remains unchanged in the pathogenesis of vascular diseases, BV values should still contain important information. We hypothesize that BV values may differ among stroke subtypes based on pathological condition.
Methods: A new type of viscometer was recently developed using an electromagnetically spinning sphere (EMS) method, which enable us to measure small amount of samples quickly and sequentially in non-contact disposable manner. We measured BV in 100 healthy outpatients and 67 acute ischemic stroke patients (atherothrombotic: 28, lacunar: 23, and cardioembolic: 16) with EMS viscometer. The relationships between BV and hematological parameters were analyzed. The measurements in the acute stroke patients were performed a total of 4 times (Day0, Day2, Day7, and Day14 from the admission).
Results: BV values in the healthy outpatients correlated more strongly with the total count of red blood cells and platelets (R2=0.6957) than with the hematocrit (R2=0.6435) in an exponential approximation. Compared with BV values in the healthy outpatients (4.57±0.76 mPa·s), Day0 BV values in the lacunar patients (5.37±1.11 mPa·s) were significantly higher (p<0.01), but those in the atherothrombotic patients (4.82±0.98 mPa·s) and in the cardioembolic patients (4.66±0.93 mPa·s) were not significantly different. In comparison between the values at Day 0 and Day 14, the lacunar patients alone showed a significant decrease from Day0 to Day14, suggesting that the lacunar patients suffered from dehydration at the onset.
Conclusion: BV values at Day0 of lacunar infarction were significantly increased, which indicated contribution of dehydration to the onset of lacunar infarction. These measurements were performed with only 0.3ml of blood quickly and sequentially; therefore, the clinical application of the EMS viscometer appears to be promising.