Augmented efficiency of regional myocardial work by ouabain.
Augmented efficiency of regional myocardial work by ouabain.
复制标题
哇巴因提高局部心肌工作效率。
DOI：
10.1093/cvr/25.11.916
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发表时间：
1991
影响因子：
10.8
通讯作者：
Weiss,HR
中科院分区：
文献类型：
--
作者：
Kedem,J;Scholtz,PM;Weiss,HR
研究目的：研究哇巴因对局部心肌力学和相应的局部心肌耗氧量的影响。测量设计的局部心肌节段长度(超声尺寸晶体)和力发展(微型应变片)。用平均搏动期间心肌缩短与相应力量的积分倍数来表示局部节段做功(=长度-力环收缩部分下的面积)。根据主动脉压和心输出量计算心外做功。分别于基础状态和哇巴因静脉滴注(7ming·kg-1·μ-1·−-1)时测定整体和局部心肌耗氧量(MVO2)。用放射性微球测量局部冠脉血流量，冰冻心肌活检用显微分光光度法检测小动、静脉血氧饱和度。这些变量被用来计算局部心肌MVO2。用动脉血氧饱和度和冠状静脉窦血氧饱和度计算左室血氧饱和度。心肌效率用局部做功/局部心肌MVO2表示。受试者10只开胸麻醉犬，体重约20 kg。测量和主要结果：心肌节段做功[从5291(SEM1067)增加到8916(2338)mm·−1·−1]明显高于局部心肌MVO2[从6.33(0.75)到8.54(0.75)ml.min−1·100g−1]。局部效率由734(78)提高到1036(160)g·mm·mlO2−1·100g−1，体外效率未见提高。短轴缩短率的增加幅度大于峰值力量发展(+76%v+38%)，这可能表明心肌顺应性增加。长度-力环向上右移。结论哇巴因可提高心肌收缩的局部效率。
Study objective— The effect of ouabain on regional myocardial mechanics and corresponding regional myocardial oxygen consumption was investigated.Design— Regional myocardial segment length (ultrasonic dimension crystals) and force development (miniature strain gauge) were measured. The integrated multiples of myocardial shortening by corresponding force during an averaged beat was used to express regional segment work (= area under the systolic portion of the length-force loop). External cardiac work was calculated from aortic blood pressure and cardiac output. Global and regional myocardial O2consumption (MVO2) were evaluated at baseline and during intravenous infusion of ouabain (7 μg·kg−1·min−1). Regional coronary blood flow was measured with radioactive microspheres, and microspectrophotometry of frozen myocardial biopsies was used to evaluate O2saturation in small arteries and veins. These variables were used to calculate regional myocardial MVO2. Arterial and coronary sinus O2saturation was used to calculate global left ventricular O2consumption. Myocardial efficiency was expressed as regional work/regional myocardial MVO2.Subjects— Ten open chest anaesthetised dogs, weight about 20 kg, were used.Measurements and main results— Ouabain increased regional myocardial segment work [from 5291(SEM 1067) to 8916(2338) mm·g−1·min−1] to a greater extent than regional myocardial MVO2[from 6.33(0.75) to 8.54(0.75) ml O2·min−1·100 g−1]. Regional efficiency was increased from 734(78) to 1036(160) g·mm·ml O2−1·100 g−1. External efficiency was not raised. Percent shortening was increased to a greater extent than peak force development (+76%v+38%), possibly indicating increased myocardial compliance. The length-force loop was shifted upward and to the right.Conclusions— Ouabain increases regional efficiency of myocardial contraction.