Myocardial Oxygen Consumption During Ventricular Contraction and Relaxation
Myocardial Oxygen Consumption During Ventricular Contraction and Relaxation
复制标题
心室收缩和舒张期间的心肌耗氧量
作者：
R. Monroe
在狗的离体心上测定了左心室耗氧量，而左心室是通过压缩空气来做功的。在所描述的制剂中，被脑室压缩的空气可以被迅速释放，并且在其周期中，脑室压力脉搏在特定的时间点反复中断。在峰值压力脉冲中断后，峰值压力增加了10%，并出现在随后的四到五次搏动中。当室内压在上升至峰值压的不同时间点被释放时，左心室耗氧量可与其中断时的压力和压力脉搏下的面积相关。当形成全压力脉搏的脑室所消耗的氧气与当两个比较的脉搏的峰值收缩压相等时，脑室内压在峰值释放时的脑室所消耗的氧气进行比较-那么脉搏中断时脑室所消耗的氧气平均是脉搏满时的91%。这些研究表明，当压力脉搏达到峰值时，心肌耗氧量基本上已经确定，而心室松弛的氧气消耗很小。
Determinations of left ventricular oxygen consumption were made in the isolated heart of a dog while the ventricle performed work by compressing air. In the described preparation the air compressed by the ventricle could be rapidly released and the ventricular pressure pulse repeatedly interrupted at specific points during its cycle. Upon interrupting the pressure pulse at its peak there was a 10% increase in peak pressure that appeared in the subsequent four to five beats. When the intraventricular pressure was released at various points during its ascent to peak pressure, left ventricular oxygen consumption could be correlated with both the pressure, at which it was interrupted, and the area under the pressure pulse. When the oxygen consumed by a ventricle developing a full pressure pulse was compared to that of a ventricle in which the intraventricular pressure was released at its peak-land when the peak systolic pressure of the two compared pulses were equal-then the oxygen consumed by the ventricle when the pulse was interrupted averaged 91% of that when the pulse was full. These studies indicate that by the time the pressure pulse has reached its peak, myocardial oxygen consumption has been largely determined, and that the oxygen cost of the ventricular relaxation is small.