Influence of ischemic zone size on nonischemic area function in the canine left ventricle.
Influence of ischemic zone size on nonischemic area function in the canine left ventricle.
复制标题
缺血区大小对犬左心室非缺血区功能的影响。
DOI：
10.1152/ajpheart.1987.252.5.h990
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Lew,WY
中科院分区：
文献类型：
--
作者：
Lew,WY
在7只麻醉犬上观察缺血区大小与非缺血区功能的关系。在左心室前心尖部、后心尖部和后心尖部中壁植入声学显微镜测量局部心功能。左心室容量分为三个水平，分别对应于7、12和19毫米汞柱的左心室舒张末压。冠状动脉左前降支远端、中段和近端依次闭塞，形成小、中、大面积的前壁缺血。每次阻断维持15-30分钟；然后将心室容量改变为三个水平，以使非缺血区的舒张末节段长度与其对照(缺血前)值相匹配。急性缺血时，在等容收缩期间缺血区出现反常延长。伴随而来的是非缺血区等容缩短的增加。非缺血区等容缩短量随缺血区大小的增加而增加，提示非缺血区缩短量越大，非缺血区等容缩短量越多。对于中度和大面积的缺血区，非缺血区的“浪费”等容缩短量在低容量时比高容量时更大。结论：缺血区对非缺血区形成机械劣势，与缺血区大小成正比，与脑室容量成反比。
The relationship between ischemic zone size and nonischemic area function was examined in seven anesthetized dogs. Regional ventricular function was measured with sonomicrometers implanted in the midwall of the anterior apex, posterior base, and posterior apex of the left ventricle. Ventricular volume was varied to three levels, corresponding to left ventricular end-diastolic pressures of 7, 12, and 19 mmHg. A small, moderate, and large area of anterior wall ischemia was produced with sequential occlusions of the distal, mid, and proximal left anterior descending coronary artery, respectively. Each occlusion was maintained for 15-30 min; then ventricular volume was varied to three levels, chosen so that end-diastolic segment lengths in the nonischemic areas were matched to their control (preischemia) values. With acute ischemia, paradoxical lengthening developed in the ischemic zone during isovolumic systole. This was accompanied by an increase in isovolumic shortening in the nonischemic areas. The amount of nonischemic area isovolumic shortening increased with increasing ischemic zone size, suggesting that more nonischemic area shortening was expended in paradoxically stretching the ischemic zone. With moderate and large areas of ischemia, the amount of "wasted" isovolumic shortening by nonischemic areas was greater at low than at high ventricular volumes. It is concluded that the ischemic zone imposes a mechanical disadvantage on nonischemic areas in direct relation to ischemic zone size and is inversely related to the ventricular volume.