Left ventricular-arterial coupling in conscious dogs.
Left ventricular-arterial coupling in conscious dogs.
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清醒狗的左心室-动脉耦合。
DOI：
10.1152/ajpheart.1991.261.1.h70
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Cheng,CP
中科院分区：
文献类型：
--
作者：
Little,WC;Cheng,CP
我们研究了左心室（LV）和动脉系统的耦合，以最大限度地提高LV每搏功（SW）和LV压力容积面积（PVA）的转换SW的标准。我们研究了8个清醒的狗，仪器测量LV压力，并确定LV容量从三个超声确定的尺寸。左室收缩末期压（PES）-容积（VES）关系由腔静脉闭塞测定。将其斜率（EES）与动脉弹性（EA）进行比较，并确定为每搏输出量的PES。静息时，反射完整，EES/EA为0.96 +/- 0.20，在多巴酚丁胺给药前和给药期间，通过输注分级剂量的苯异丙胺和硝普钠，EES/EA在很宽的范围（0.18-2.59）内变化。当EES/EA等于0.99 +/- 0.15时，在恒定变力状态和舒张末期容积（VED）下发生最大LV SW。在恒定VED和收缩状态下，当EES/EA在0.56和2.29之间时，SW在其最大值的20%以内。LV PVA向SW的转化率随EES/EA的增加而增加。观察到的SW与EES/EA和SW/PVA与EES/EA的关系的形状与LV PES-VES和动脉PES-每搏输出量关系的理论考虑所预测的形状相似。我们得出结论，当EES和EA相等时，LV和动脉系统在恒定VED下产生最大SW;然而，SW与EES/EA的关系有一个广阔的平台。只有当EA大大超过EES时，SW才会大幅下降。然而，PVA向SW的转化率随着EES/EA的增加而增加。这些观察结果支持在压力-容积平面中分析LV-动脉耦合的实用性。
We investigated the criteria for the coupling of the left ventricle (LV) and the arterial system to maximize LV stroke work (SW) and the transformation of LV pressure-volume area (PVA) to SW. We studied eight conscious dogs that were instrumented to measure LV pressure and determine LV volume from three ultrasonically determined dimensions. The LV end-systolic pressure (PES)-volume (VES) relation was determined by caval occlusion. Its slope (EES) was compared with the arterial elastance (EA) and determined as PES per stroke volume. At rest, with intact reflexes, EES/EA was 0.96 +/- 0.20 EES/EA was varied over a wide range (0.18-2.59) by the infusion of graded doses of phenylephrine and nitroprusside before and during administration of dobutamine. Maximum LV SW, at constant inotropic state and end-diastolic volume (VED), occurred when EES/EA equaled 0.99 +/- 0.15. At constant VED and contractile state, SW was within 20% of its maximum value when EES/EA was between 0.56 and 2.29. The conversion of LV PVA to SW increased as EES/EA increased. The shape of the observed relations of the SW to EES/EA and SW/PVA to EES/EA was similar to that predicted by the theoretical consideration of LV PES-VES and arterial PES-stroke volume relations. We conclude that the LV and arterial system produce maximum SW at constant VED when EES and EA are equal; however, the relation of SW to EES/EA has a broad plateau. Only when EA greatly exceeds EES does the SW fall substantially. However, the conversion of PVA to SW increases as EES/EA increases. These observations support the utility of analyzing LV-arterial coupling in the pressure-volume plane.