Responses of myocardial high energy phosphates and wall thickening to prolonged regional hypoperfusion induced by subtotal coronary stenosis.
Responses of myocardial high energy phosphates and wall thickening to prolonged regional hypoperfusion induced by subtotal coronary stenosis.
复制标题
心肌高能磷酸盐和壁增厚对冠状动脉次全狭窄引起的长期局部低灌注的反应。
DOI：
10.1002/mrm.1910300106
复制
发表时间：
1993
影响因子：
3.3
通讯作者：
Uğurbil,K
中科院分区：
文献类型：
--
作者：
Zhang,J;Path,G;Chepuri,V;Xu,Y;Yoshiyama,M;Bache,RJ;From,AH;Uğurbil,K
心肌对长期或慢性缺血的反应可能不同于充分记录的在灌注不足发作后急性发生的变化。因此，我们在一个装有仪器的犬模型中，使用空间定位光谱技术，以实现跨壁分化，心肌HEP和Pilevels以及持续冠状动脉狭窄引起的长期缺血期间的壁增厚。结果表明，冠状动脉次全闭塞引起心肌HEP含量立即和跨壁不均匀降低和Pi/CP比值增加;然而，在持续轻度低灌注期间，发生代谢变化，导致CP（但不是ATP）的统计学显著恢复和Pi的消失，从而持续减少的血流量和氧供应。在释放闭塞后，先前缺血的肌肉恢复了血流，并且其部分（但不是全部）缺血前收缩功能没有HEP水平的平行变化。结论：正常的HEP和Pilevels不能等同于没有灌注不足或NMR波谱对缺血不敏感。相反，必须同时进行功能和光谱测量，以区分缺血心肌是否适应低灌注。
The response of the myocardium to prolonged or chronic ischemia may differ from the well documented changes that occur acutely subsequent to the onset of hypoperfusion. Therefore, we have examined in an instrumented canine model and using spatially localized spectroscopy to achieve transmural differentiation, the myocardial HEP andPilevels as well as wall thickeningin situduring prolonged ischemia induced by sustained coronary artery stenosis. The results demonstrate that subtotal coronary artery occlusion causes immediate andtransmurallyinhomogeneous decreases in the myocardial HEP content and increase in thePi/CP ratio; however, during prolonged mild hypoperfusion, metabolic changes occur which lead to statistically significant recovery of CP (but not ATP) and disappearance ofPidespite the persistence of reduced blood flow and oxygen supply. Upon release of the occlusion, the previously ischemic muscle recovered blood flow, and some (but not all) of its preischemic contractile function without parallel changes in the HEP levels. It is concluded that normal HEP andPilevels cannot be equated with either the absence of underperfusion orinsensitivityof NMR spectroscopy to ischemia. Rather, it is imperative that bothfunctionalandspectroscopicmeasurements are performed simultaneously to distinguish between ischemic myocardium which is adapted versus unadapted to the hypoperfusion.