Effects of global ischemia on the diastolic properties of the left ventricle in the conscious dog.
Effects of global ischemia on the diastolic properties of the left ventricle in the conscious dog.
复制标题
全身缺血对清醒狗左心室舒张特性的影响。
DOI：
10.1161/01.cir.71.3.610
复制
发表时间：
1985
期刊：
影响因子：
37.8
通讯作者：
Anderson,RW
中科院分区：
文献类型：
--
作者：
Visner,MS;Arentzen,CE;Parrish,DG;Larson,EV;O'Connor,MJ;Crumbley3rd,AJ;Bache,RJ;Anderson,RW
局部心肌缺血期间发生的局部舒张力学改变（蠕变和心肌硬度增加）可能是缺血心肌和周围非缺血心肌之间相互作用的结果，而不是缺血的直接结果。因此，当整个左心室缺血时，可能不会发生类似的变化。因此，当整个左心室缺血时，可能不会发生类似的变化。为了探讨这一命题，左心室舒张力学进行了研究，在7个慢性仪器清醒狗在全球左心室缺血。超声测量左室前后轴、无隔壁轴、基底心尖轴。用微压计测量左、右心室压力。左心房注射15微米放射性微球测量心肌血流量。左冠状动脉主干液压收缩导致左心室内膜下平均血流量减少54%，从而引起全左心室缺血。根据椭球壳理论计算左心室容积、中壁周长和中壁周向应力。为了从腔静脉闭塞期间收集的舒张期数据构建压力-应变和应力-应变关系，将所有测量和计算的尺寸归一化为拉格朗日应变（无应力尺寸的部分延伸）。在缺血期间，蠕变（无应力尺寸的伸长）发生在三个左心室轴中的每一个。前后轴的平均无应力尺寸从5.39 +/- 0.53增加到5.85 +/- 0.50 cm（p小于或等于0.05）;无隔膜壁无应力尺寸从5.11 +/- 0.53增加至5.72 +/- 0.80 cm（p小于或等于0.05）;基底-顶点无应力尺寸从7.04 +/- 0.61增加到7.25 +/- 0.65 cm（p小于或等于0.05）。舒张期中壁周向应力和应变之间的关系随着缺血向上和向左移动，表明内在心肌硬度增加。由于这些机械改变，左心室腔室顺应性降低，表现为舒张压-容积应变关系的急剧变化。缺血时，左室三个空间轴均未出现收缩期膨出或收缩期不同步缩短。（400字处截断摘要）
The alterations in regional diastolic mechanics that occur during regional myocardial ischemia (creep and increased myocardial stiffness) may be the result of interactions between the ischemic and surrounding nonischemic myocardium rather than the direct result of ischemia. Thus similar changes may not occur when the entire left ventricle is ischemic. Thus similar changes may not occur when the entire left ventricle is ischemic. To investigate this proposition, left ventricular diastolic mechanics were studied in seven chronically instrumented conscious dogs during global left ventricular ischemia. The anterior-posterior, septal-free wall, and base-apex axes of the left ventricle were measured with ultrasonic dimension transducers. Left and right ventricular pressures were measured with micromanometers. Myocardial blood flows were measured with left atrial injections of 15 microns radioactive microspheres. Global left ventricular ischemia was induced by hydraulic constriction of the left main coronary artery, which resulted in a 54% decrease in mean left ventricular subendocardial blood flow. Left ventricular volume, midwall circumference, and midwall circumferential stress were calculated from ellipsoidal shell theory. To construct pressure-strain and stress-strain relationships from diastolic data collected during vena caval occlusions, all measured and calculated dimensions were normalized to Lagrangian strains (fractional extension from unstressed dimension). During ischemia, creep (elongation of unstressed dimension) occurred in each of the three left ventricular axes. The mean unstressed dimension of the anterior-posterior axis increased from 5.39 +/- 0.53 to 5.85 +/- 0.50 cm ( p less than or equal to .05); the septal-free wall unstressed dimension increased from 5.11 +/- 0.53 to 5.72 +/- 0.80 cm (p less than or equal to .05); and the base-apex unstressed dimension increased from 7.04 +/- 0.61 to 7.25 +/- 0.65 cm (p less than or equal to .05). The relationship between diastolic midwall circumferential stress and strain shifted upward and to the left with ischemia, indicating that an increase in intrinsic myocardial stiffness had occurred. As a result of these mechanical alterations, there was a decrease in left ventricular chamber compliance that was manifested by a leftward shift of the diastolic pressure-volume strain relationship. Neither systolic bulging nor dysynchronous systolic shortening occurred in any of the three left ventricular spatial axes during ischemia.(ABSTRACT TRUNCATED AT 400 WORDS)