Sasayama S, Asanoi H
Second Department of Internal Medicine, Ioyama Medical and Pharmaceutical University, Japan.
Am J Med. 1991 May 29;90(5B):14S-18S. doi: 10.1016/0002-9343(91)90267-2.
A number of experimental studies have demonstrated the optimal coupling between the ventricle and arterial load, under physiologic and pathologic circumstances, directed to produce maximal stroke work. We investigated matching of the ventricular properties, quantified by the slope of end-systolic pressure-volume relationship, with arterial load properties, expressed by the slope of end-systolic pressure-stroke volume relationship. In normal subjects, with ejection fraction of greater than or equal to 60%, ventricular elastance was nearly twice as large as arterial elastance. This condition affords maximal mechanical efficiency. In patients with moderate heart failure, with ejection fraction of 40-59%, ventricular elastance was almost equal to arterial elastance. This condition affords maximal stroke work from a given end-diastolic volume. In patients with severe heart failure, with ejection fraction of less than 40%, ventricular elastance was less than half of arterial elastance, which resulted in increased potential energy and decreased work efficiency. Ventriculoarterial coupling is normally set toward higher left ventricular work efficiency, whereas in patients with moderate cardiac dysfunction, ventricular and arterial properties are matched, in order to maximize stroke work at the expense of work efficiency. Neither the stroke work nor work efficiency is near maximum for patients with severe cardiac dysfunction.
许多实验研究表明，在生理和病理情况下，心室与动脉负荷之间存在最佳耦合，旨在产生最大的搏功。我们研究了通过收缩末期压力-容积关系斜率量化的心室特性与通过收缩末期压力-搏出量关系斜率表示的动脉负荷特性之间的匹配情况。在正常受试者中，射血分数大于或等于60%，心室弹性几乎是动脉弹性的两倍。这种情况可提供最大的机械效率。在中度心力衰竭患者中，射血分数为40%-59%，心室弹性几乎等于动脉弹性。这种情况可从给定的舒张末期容积中获得最大的搏功。在重度心力衰竭患者中，射血分数小于40%，心室弹性小于动脉弹性的一半，这导致势能增加和工作效率降低。心室动脉耦合通常设定为较高的左心室工作效率，而在中度心功能不全患者中，心室和动脉特性相匹配，以便以工作效率为代价最大化搏功。对于重度心功能不全患者，搏功和工作效率均未接近最大值。
