LINEARITY OF THE FRANK-STARLING RELATIONSHIP IN THE INTACT HEART - THE CONCEPT OF PRELOAD RECRUITABLE STROKE WORK
LINEARITY OF THE FRANK-STARLING RELATIONSHIP IN THE INTACT HEART - THE CONCEPT OF PRELOAD RECRUITABLE STROKE WORK
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DOI：
10.1161/01.cir.71.5.994
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发表时间：
1985-01-01
期刊：
影响因子：
37.8
通讯作者：
RANKIN, JS
中科院分区：
文献类型：
--
作者：
GLOWER, DD;SPRATT, JA;RANKIN, JS
Frank-Starling关系通常以充盈压力作为前负荷的指标进行检查，导致曲线函数在较高的充盈压力下达到平台。为了进一步研究这种关系，在完整的心脏，32只狗长期装备左心室和胸膜微压计和区域（10只狗）或全球（22只狗）超声尺寸传感器。植入后7天，在清醒状态下记录左心室压力和局部或整体尺寸。自主神经阻滞后，前负荷变化的腔静脉闭塞。通过计算局部或整体每搏作功来评估心肌功能，并通过舒张末期段长度或腔室容积来测量前负荷。每项研究中，每搏功与舒张末期节段长度或心腔容积之间的关系（称为前负荷可复搏功关系）高度线性（平均r = 0.97），并且可以通过斜率（Mw）和x截距（Lw）进行量化。以往的每搏功与充盈压之间的非线性关系似乎反映了指数舒张压-容积曲线。在生理范围内的收缩动脉压所产生的输液硝普钠或phenyllephaline，没有显着的变化，观察在Mw或LW在正常的狗。Ca输注使区域和全球Mw均增加71 . ±. 19%和65 .+-. 9%（P < 0.02），Lw无明显变化。为了使心室几何形状和心率标准化，根据周向应力-应变数据计算每搏作功，并将其转换为心肌功率输出，然后将其与舒张末期周向应变作图。这种关系也是高度线性的，斜率Mmp（心肌的mW/cm 3）被认为是独立于负荷、几何形状和心率的内在心肌性能的潜在指标。
The Frank-Starling relationship generally is examined with filling pressure as the index of preload, resulting in a curvilinear function that plateaus at higher filling pressures. To investigate this relationship further in the intact heart, 32 dogs were chronically instrumented with left ventricular and pleural micromanometers and with regional (10 dogs) or global (22 dogs) ultrasonic dimension transducers. Seven days after implantation, left ventricular pressure and regional or global dimensions were recorded in the conscious state. After autonomic blockade, preload was varied by vena caval occlusion. Myocardial function was assessed by calculating regional or global stroke work, and preload was measured as end-diastolic segment length or chamber volume. The relationship between stroke work and either end-diastolic segment length or chamber volume (termed the preload recruitable stroke work relationship) was highly linear in every study (mean r = 0.97) and could be quantified by a slope (Mw) and x-intercept (Lw). Previous nonlinear relationships between stroke work and filling pressure seemed to reflect the exponential diastolic pressure-volume curve. Over the physiologic range of systolic arterial pressures produced by infusion of nitroprusside or phenylephrine, no significant change was observed In Mw or Lw in the normal dog. Ca infusion increased both regional and global Mw by 71 .+-. 19% and 65 .+-. 9%, respectively, (P < 0.02), with no significant change in Lw. To normalize for ventricular geometry and heart rate, stroke work was computed from circumferential stress-strain data and converted to myocardial power output, which was then plotted against end-diastolic circumferential strain. This relationship also was highly linear and the slope, Mmp (mW/cm3 of myocardium), is proposed as a potential measure of intrinsic myocardial performance independent of loading, geometry and heart rate.