The effect of intramural small coronary artery narrowing on microcirculation in L-NAME induced model mini pig

心肌内小冠状动脉狭窄对心肌局部血流灌注的影响：应用多普勒和心肌声学造影对L-NAME治疗的猪的实验研究虽然心肌内小冠状动脉的结构异常已被提出，但其对心肌局部心肌血流灌注的作用尚不清楚。我们先前报道，高频探头经胸多普勒超声心动图是一种可以检测肥厚型心肌病患者心肌内小冠状动脉狭窄病变的技术。然而，由于方法学的限制，小冠状动脉狭窄与其对微循环的作用之间的关系仍存在争议。另一方面，心肌声学造影是一种显示微循环功能障碍(小冠状动脉下游)作为密度变化的方法。L治疗的猪是一种有…的动物模型小冠状动脉狭窄较多，无心外膜冠状动脉狭窄。我们假设小冠状动脉上游狭窄会影响局部血流灌注障碍，并用彩色多普勒超声心动图检测心肌内小冠状动脉狭窄对心肌灌注异常的影响，并用心肌声学造影对L-NAME治疗的开胸猪进行心肌声学造影检查。5头经L治疗的猪中，有3头能预测到小冠状动脉狭窄。4头猪中有2头在外周输注三磷酸腺苷的过程中，心肌声学造影显示冠状动脉小狭窄下游心肌低灌注量。我们关于冠状动脉小狭窄对局部心肌低灌注量的产生有重要作用的假说在本研究中得到了部分结果，但其正确性还有待进一步的证实。较少

The effect of the intramyocardial small coronary artery stenosis on the regional perfusion in the myocardium: Experimental study in L-NAME treated pigs using Doppler and myocardial contrast echocardiographyAlthough the structural abnormalities of the intramyocardial small coronary artery are proposed, its role for regional myocardial perfusion is unknown. We previously reported that transthoracic Doppler echocardiography using a high frequency transducer is a technique which can detect the stenotic lesion in the intramyocardial small coronary artery in patients with hypertrophic cardiomyopathy. However, the relation of the stenosis of the small coronary artery and its role for microcirculation is controversial because of the methodological limitations. On the other hand, myocardial contrast echocardiography is method which demonstrates the microcirculatory dysfunction (downstream of the small coronary artery) as changes of the density. L-NAME treated pig is an animal model which has a … More stenosis of the small coronary artery without epicardial coronary artery stenosis. We hypothesized that the upstream stenosis of the small coronary artery would affect the regional perfusion disturbance, and examined whether the intrammyocardial small coronary artery stenosis by color Doppler echocardiography can affect the myocardial perfusion abnormalities by myocardial contrast echocardiography during ATP infusion in L-NAME treated open chest pigs.Prediction of Doppler echocardiographic demonstration of the small coronary artery stenosis was demonstrated in 3 of 5 pigs after L-NAME treated pigs. Myocardial hypoperfusion downstream of the small coronary artery stenosis was demonstrated by myocardial contrast echocardiography during peripheral ATP infusion in 2 of 4 pigs. Our hypothesis of small coronary artery stenosis has an important role for producing the regional myocardial hypoperfusion was partially obtained in this study while further confirmation of the validity is needed in the future. Less