Pacella John J, Kameneva Marina V, Villanueva Flordeliza S
Cardiovascular Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
Biorheology. 2009;46(5):365-78. doi: 10.3233/BIR-2009-0548.
We have shown that drag-reducing polymers (DRP) reduce microvascular resistance and improve myocardial perfusion during coronary stenosis. We used myocardial contrast echocardiography (MCE) and mathematical modeling to define the DRP microvascular effects. A non-flow-limiting left anterior descending (LAD) stenosis was created in 8 dogs. Intramyocardial blood volume, RBC velocity and flow in the LAD and circumflex (CX) beds were obtained from MCE at baseline, and in hyperemia, stenosis, hyperemia + stenosis, and hyperemia + stenosis + DRP. Microvascular resistances were calculated from a lumped-parameter model. During stenosis + hyperemia, LAD bed microvascular resistance increased (p<0.015), and capillary volume (p<0.002) and red cell velocity (p<0.0004) decreased relative to baseline. With DRP, during stenosis and hyperemia, LAD bed microvascular resistance decreased (p<0.04); there was an increase in capillary volume (p<0.007), RBC velocity (p<0.006), and flow (p<0.05). Decreased model-computed capillary resistance accounted for the reduction in LAD bed resistance after DRP. We conclude that DRP improve flow reserve during coronary stenosis by modulating capillary resistance. Primary modification of the rheological properties of blood to affect capillary resistance is a novel approach for the treatment of acute coronary syndromes.
我们已经表明，减阻聚合物（DRP）可降低微血管阻力，并在冠状动脉狭窄期间改善心肌灌注。我们使用心肌对比超声心动图（MCE）和数学模型来确定DRP的微血管效应。在8只犬中制造了非血流限制性左前降支（LAD）狭窄。在基线、充血、狭窄、充血 + 狭窄以及充血 + 狭窄 + DRP状态下，通过MCE获得心肌内血容量、红细胞速度以及LAD和回旋支（CX）床的血流。微血管阻力由集总参数模型计算得出。在狭窄 + 充血期间，相对于基线，LAD床微血管阻力增加（p<0.015），毛细血管容积（p<0.002）和红细胞速度（p<0.0004）降低。使用DRP时，在狭窄和充血期间，LAD床微血管阻力降低（p<0.04）；毛细血管容积（p<0.007）、红细胞速度（p<0.006）和血流（p<0.05）增加。模型计算的毛细血管阻力降低解释了DRP后LAD床阻力的降低。我们得出结论，DRP通过调节毛细血管阻力来改善冠状动脉狭窄期间的血流储备。对血液流变学特性进行原发性改变以影响毛细血管阻力是治疗急性冠状动脉综合征的一种新方法。
