摘要
目的 观察犬在正常状态和心肌收缩力发生变化时心肌背向散射积分平均值 (AII)及其随心动周期变化幅度 (CVIB)的改变 ,探讨AII及CVIB的变化规律。方法 选用成年杂种犬 7只 ,麻醉后分别在静脉注射多巴酚丁胺和心得安前后获取室间隔基底部及左室后壁心肌组织的心肌背向散射积分 (IBS)变化曲线图 ,同时测出AII和CVIB。结果 在静脉注射多巴酚丁胺和心得安前后 ,室间隔基底部和左室后壁心肌AII均无明显改变 (P >0 .0 5 ) ;静脉注射多巴酚丁胺后 ,其CVIB比用药前明显升高 (室间隔基底部 :9.5± 0 .6vs 6.8± 0 .3 ,P <0 .0 0 1;左室后壁 :10 .9± 0 .7vs 8.5± 0 .3 ,P <0 .0 0 1) ;静脉注射心得安后 ,其CVIB比用药前明显降低 (室间隔基底部 :5 .2±0 .3vs 7.1± 0 .2 ,P <0 .0 0 1;左室后壁 :6.3± 0 .6vs 8.6± 0 .3 ,P <0 .0 0 1)。结论 AII和CVIB的变化有着不同的组织学和生理学基础。心肌收缩力的改变并不影响AII ,却能使CVIB发生明显变化。当心肌收缩力增强时 ,CVIB明显升高 ;当心肌收缩力减弱时 ,CVIB明显降低。
Objective To evaluate the effects of left ventricular contractility on the changes of average image intensity(AII) of the myocardial integrated backscatter(IBS) and cyclic variation in IBS(CVIB).Methods Seven adult mongrel dogs were chosen to be studied.The curves of myocardial IBS of several cardiac cycle were acquired to calibrate the magnitude of AII and CVIB before and after dobutamine or propranolol infusion.Results Dobutamine or propranolol did not affect the magnitude of AII (P> 0.05 ) of the IBS.However,dobutamine produced a significant increase in the magnitude of CVIB(basal septum: 9.5 ± 0.6 vs 6.8 ± 0.3 ,P< 0.001 ;posterio wall: 10.9 ± 0.7 vs 8.5± 0.3 ,P< 0.001 ) and propranolol significantly decrease the magnitude of CVIB(basal septum: 5.2 ± 0.3 vs 7.1± 0.2 ,P< 0.001 ;posterio wall: 6.3 ± 0.6 vs 8.6 ± 0.3 ,P< 0.001 ).Conclusions The changes of the magnitude of AII and CVIB have been demonstrated to reflect different physiological and pathological changes respectively.The contractility alteration can not affect the magnitude of AII,but can produce significant change in CVIB.The increase of left ventricular contractility results in a significant rise of the magnitude of CVIB and the decrease of left ventricular contractility results in a significant fall of the magnitude of CVIB.The correlation between the contractility and the magnitude of CVIB was demonstrated.
出处
《中华超声影像学杂志》
CSCD
2002年第8期491-493,共3页
Chinese Journal of Ultrasonography
