顿抑心肌背向散射积分周期变化幅度与一氧化氮及一氧化氮合酶关系的实验研究

Experimental study on the relation between cyclic variation of integrated backscatter and nitric oxide and nitric oxide synthase in stunned myocardium

目的 探讨顿抑心肌背向散射积分周期变化幅度 (CVIB)与一氧化氮 (NO)、一氧化氮合酶(NOS)和反映收缩功能的局部室壁增厚率 (WT)的相关关系 ,为CVIB应用于临床检测存活心肌的可靠性和准确性提供客观支持依据。方法 建立犬顿抑心肌模型 ,分别观察左冠状动脉前降支 (LAD)结扎前、结扎后 30min以及再灌注 5min、1 5min、30min后CVIB和WT的动态变化 ,检测各时间点的冠状静脉窦血NO和NOS ,并分析CVIB与WT、NO和NOS的相关性。结果 冠状动脉结扎后 30min ,各指标均显著降低 (P <0 .0 0 0 1 ) ,再灌注后均逐渐恢复 ,动态变化趋势相似 ;于再灌注后 30min ,NO和NOS完全恢复到基础值水平 ,而CVIB和WT分别只恢复到基础值的 60 .91 %± 1 1 .2 7%和 54 .54 %± 1 3 .1 7% (P <0 .0 0 0 1 ) ;并且各观察时间点的CVIB与WT、NO及NOS均有良好的相关性 ,相关系数在 0 .71 2～ 0 .842之间 ,均 P <0 .0 5。结论 CVIB不仅与反映心肌局部收缩功能的WT关系密切 ,而且与影响顿抑心肌收缩功能的NO及NOS具有良好的相关性 ,是一项检测存活心肌的准确。

Objective To investigate the correlation between cyclic variation of integrated backscatter (CVIB) and nitric oxide (NO), nitric oxide synthase (NOS), wall thickening (WT) in stunned myocardium, and to provide objective and supportive basis for accuracy and reliability of CVIB which is applyied in detecting viable myocardium clinically.Methods Myocardial stunning models of dogs were made. The dynamic changes of CVIB and WT before and after LAD occlusion 30 min,and at 5 min, 15 min,30 min after reperfusion were measured. NO and NOS in coronary sinus blood were examined at the corresponding examining time. The correlation between CVIB and WT, NO, NOS was analyzed.Results After LAD occlusion 30min, the variables were significantly decreased (P< 0.000 1 ), and gradually recovered after reperfusion. The tendency of these variables was similar. After reperfusion 30 min, the values of NO and NOS were all returned to baseline, but CVIB and WT only reached to 60.91 %± 11.27 % and 54.54 %± 13.17 %of the baseline(P< 0.000 1 ), respectively. The correlation between CVIB and WT, NO, NOS was better at the different examining time, and the correlation coefficients were 0.712 ～ 0.842 (P< 0.05 ). Conclusions The relation between CVIB and WT, which reflects the regional ventricular systolic function, was closer.There is also a better correlation between CVIB and NO, NOS, which affect the systolic function of stunned myocardium. Consequently, CVIB is an accurate and reliable variable in detecting viable myocardium.