EARLY INCREASE IN LEFT VENTRICULAR COMPLIANCE AFTER MYOCARDIAL-INFARCTION
EARLY INCREASE IN LEFT VENTRICULAR COMPLIANCE AFTER MYOCARDIAL-INFARCTION
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DOI：
10.1172/jci106849
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发表时间：
1972-01-01
影响因子：
15.9
通讯作者：
DIAMOND, G
中科院分区：
文献类型：
--
作者：
FORRESTER, JS;SWAN, HJC;DIAMOND, G
左心室（LV）压力-容积（P-V）关系是几个决定因素的结果，包括初始心室容积、几何形状和室壁硬度。这些决定因素之一，左室壁刚度的定量指标，开发从孤立的P-V关系的数学分析。由于这种关系是指数关系，刚度（dP/dV）可以用方程dP/dV = aP + B表示，其中a和b是常数。该常数被称为被动弹性模量，与压力和体积无关，仅因几何形状的变化而略有变化，因此主要受壁刚度变化的影响。通过测定8只正常犬心脏和5只急性心肌梗死后1小时的心脏的被动弹性模量来评估LV壁刚度。正常犬左心室的被动弹性模量值为0.099±0.006 cc-1。在5个梗塞心脏中，P-V曲线相对于对照组有适度的但统计学上不显著的偏移，使得对于相同的压力，梗塞心脏包含更大的体积。被动弹性模量下降41%，为0.057± 0.006cc-1（P< 0.001）。因此，虽然LV壁硬度可能会在心肌梗死的后期增加，但可以得出结论，它在梗死后1小时显著降低。被动弹性模量的计算提供了一种检测这种变化的灵敏手段，而单独的P-V曲线通常不敏感。
The left ventricular (LV) pressure-volume (P-V) relationship is a resultant of several determinants, including initial ventricular volume, geometry, and wall stiffness. A quantitative index of one of these determinants, LV wall stiffness, was developed from a mathematical analysis of the isolated P-V relationship. Since this relationship was exponential, stiffness (dP/dV) could be expressed by the equation dP/dV = aP + b, whereaandbare constants. Theaconstant, termed the passive elastic modulus, was independent of both pressure and volume, was modified only slightly by changes in geometry, and thus was primarily affected by changes in wall stiffness. LV wall stiffness was assessed by determination of the passive elastic modulus in eight normal canine hearts and in five hearts 1 hr after acute myocardial infarction. The value of the passive elastic modulus for the normal canine LV was found to be 0.099±0.006 cc-1. In the five infarcted hearts there was a modest, but statistically insignificant, shift of the P-V curves from control, such that for the same pressure the infarcted hearts contained greater volume. However, the passive elastic modulus decreased 41% to 0.057±0.006 cc-1(P< 0.001). Thus, although LV wall stiffness may increase later in the course of myocardial infarction, it is concluded that it was significantly decreased 1 hr after infarction. Calculation of the passive elastic modulus provided a sensitive means of detecting such changes, whereas P-V curves alone were generally insensitive.