Subendocardial and subepicardial wall thickening during ischemia in exercising dogs.
Subendocardial and subepicardial wall thickening during ischemia in exercising dogs.
复制标题
运动犬缺血时心内膜下和心外膜下壁增厚。
DOI：
10.1161/01.cir.78.5.1267
复制
发表时间：
1988
期刊：
影响因子：
37.8
通讯作者：
Bache,RJ
中科院分区：
文献类型：
--
作者：
Homans,DC;Sublett,E;Lindstrom,P;Nesbitt,T;Bache,RJ
为了确定运动犬的缺血是否与心外膜下增厚相对于心内膜下增厚的保留相关，10只犬长期装备有旋动脉流量探头、液压封堵器和成对的超声微晶，用于确定旋动脉分布中的壁厚。一对晶体跨越整个心室壁（透壁），另一对跨越心室壁的外半部。内壁厚度计算为透壁壁厚度和外壁厚度之差。狗进行控制跑步机运动和运动与冠状动脉狭窄，减少回旋动脉血流到休息控制水平。静息时透壁、内部和外部区域的收缩期增厚百分比分别为21.3 ± 11.8%、35.5 ± 20.3%和10.3 ± 5.0%（平均值± SD）。在无狭窄的运动期间，收缩期增厚增加到对照组外壁晶体的143 +/- 37%和对照组壁内部的137 +/- 26%。在运动过程中，增加冠状动脉狭窄导致外壁增厚减少至对照的17.7 +/- 28.5%，壁内部分增厚减少至对照的40.1 +/- 32.3%;这些没有显著差异。相比之下，在运动过程中，回旋支动脉狭窄（25.0 +/- 16.0%）的标准化内壁血流量明显低于壁的外部（48.5 +/- 20.9%）。此外，内壁增厚和内壁血流量变化之间存在密切关系（r = 0.84），而外壁血流量变化和功能之间的关系非常弱（r = 0.62; p = 0.04）。在运动狗的局部缺血期间，外壁增厚被抑制，与外壁血流的减少不成比例，并且相对于内壁增厚不被保留。
To determine whether ischemia in the exercising dog is associated with preservation of subepicardial thickening relative to subendocardial thickening, 10 dogs were chronically instrumented with circumflex artery flow probes, hydraulic occluders, and pairs of ultrasonic microcrystals for determination of wall thickness in the circumflex artery distribution. One pair of crystals spanned the entire ventricular wall (transmural), and the other spanned the outer half of the ventricular wall. Inner wall thickness was computed as the difference between transmural wall thickness and outer wall thickness. Dogs performed control treadmill exercise and exercise with a coronary stenosis that reduced circumflex artery flow to resting control levels. Percent systolic thickening at rest for the transmural, inner, and outer regions was 21.3 +/- 11.8%, 35.5 +/- 20.3%, and 10.3 +/- 5.0% (mean +/- SD), respectively. During exercise without stenosis, systolic thickening increased to 143 +/- 37% of control for outer wall crystals and 137 +/- 26% of control for the inner portion of the wall. During exercise, the addition of a coronary stenosis caused a reduction in thickening to 17.7 +/- 28.5% of control for the outer wall and 40.1 +/- 32.3% of control for the inner portion of the wall; these were not significantly different. In contrast, normalized inner wall blood flow during exercise with circumflex artery stenosis (25.0 +/- 16.0%) was significantly less than for the outer portion of the wall (48.5 +/- 20.9%). Further, there was a close relation between changes in inner wall thickening and inner wall blood flow (r = 0.84), whereas there was only a very weak relation between changes in outer wall blood flow and function (r = 0.62; p = 0.04). During ischemia in the exercising dog, outer wall thickening is depressed out of proportion to reductions in outer wall blood flow and is not preserved relative to inner wall thickening.