Electroaugmentation of Ventricular Performance and Oxygen Consumption by Repetitive Application of Paired Electrical Stimuli
Electroaugmentation of Ventricular Performance and Oxygen Consumption by Repetitive Application of Paired Electrical Stimuli
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通过重复应用成对电刺激来电增强心室性能和耗氧量
DOI：
10.1161/01.res.16.4.332
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发表时间：
1965
影响因子：
20.1
通讯作者：
E. Braunwald
中科院分区：
文献类型：
--
作者：
J. Ross;E. Sonnenblick;G. Kaiser;P. Frommer;E. Braunwald
当在不应期之后立即向心室传递去极化刺激时，几乎不会发生期前收缩，并且重复的成对刺激会导致心室性能显着且持续的改善，这被称为电增强。本研究描述了这种增强及其对心肌耗氧量 (MVO2) 的影响。在对 14 只狗进行的 45 项实验中，平均主动脉压和每搏输出量通过右心旁路保持恒定，从相同收缩率的单一刺激改为配对刺激显着提高了左心室的性能，射血时间缩短、左心室 dp/dt、每搏功率和峰值射血率增加，有时甚至舒张末压下降也证明了这一点。给予利血平或奈沙利特后也获得类似的结果。在对 11 只狗进行的 15 项实验中，单次刺激和配对刺激期间左心室的每搏输出量是不同的。配对刺激期间左心室性能的改善总是通过收缩速度的增加和舒张末期压力与每搏功率平均和峰值射血率相关的曲线的向上位移来证明，有时通过将舒张末期压力与每搏输出量和每搏功相关的曲线向上位移来证明。在八项实验中，MV˙O2 是在单次刺激和配对刺激、每搏输出量、平均主动脉压和收缩率保持恒定的情况下测定的。配对刺激始终会增加 MV˙O2，平均增加 35%。尽管 MV˙O2 上升，但紧张时间指数始终下降。这些研究表明，重复的配对刺激对哺乳动物的心室产生强大而持续的正性肌力影响，并且在外部世界相对恒定的水平下，伴随这种效应的心室收缩速度的增加导致MV˙O2的增加。
When a depolarizing stimulus is delivered to the ventricle immediately following the refractory period, little extrasystolic contraction occurs and repetitive paired stimulation then results in a marked and sustained improvement of ventricular performance which has been termed electroaugmentation. The present study characterizes this augmentation and its effects on myocardial oxygen consumption (MVO2). In 45 experiments on 14 dogs in which mean aortic pressure and stroke volume were held constant by right heart bypass, a change from single to paired stimulation at identical contraction rates markedly increased the performance of the left ventricle as evidenced by shortening of ejection time increase in left ventricular dp/dt, stroke power, and peak ejection rate, and sometimes a fall in end diastolic pressure. Similar resul were obtained after administration of resepine or nethalide. In 15 experiments on 11 dogs the stroke volume of the left ventricle was varied during single and paired stimulation. Improvement in left ventricular performance during paired stimulation was always evidenced by increased speed of contractic and an upward displacement of the curvesrelating end diastolic pressure to stroke powe mean and peak ejection rates, and some times by an upward displacement of the curves relating end diastolic pressure to stroke volume and stroke work. In eight experiments MV˙O2 was determined during single and paired stimulation, stroke volume, mean aortic pressure, and contraction rate being held constant. Paired stimulation always increased MV˙O2 the average increase being 35%. Despite the rise in MV˙O2, a reduction in the tension-time index always occurred. These studies indicate that repetitive paired stimulation exerts a powerful and sustained positive inotropic in fluence on the mammalian ventricle and that at a relatively constant level of external world the increased velocity of ventricular contraction which accompanies this effect results in an increase in MV˙O2.