Mechanisms of mitral valve motion during diastole.
Mechanisms of mitral valve motion during diastole.
复制标题
舒张期二尖瓣运动的机制。
DOI：
10.1152/ajpheart.1981.241.3.h389
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Frater,RW
中科院分区：
文献类型：
--
作者：
Yellin,EL;Peskin,C;Yoran,C;Koenigsberg,M;Matsumoto,M;Laniado,S;McQueen,D;Shore,D;Frater,RW
为了检查二尖瓣在二尖瓣中段和关闭时的运动机制，我们同时测量了二尖瓣血流（电磁）、瓣膜运动（回波）和房室压（微压计）。峰值瓣膜偏移（E点）发生在打开后早期（46 +/- 7 ms），并且始终先于峰值血流;因此，舒张中期关闭运动（EF斜率）不是由于血流减速或涡流形成。峰值流量的较大变化伴随着阀门偏移的较小变化（变化系数分别为41和12%）。我们的结论是，瓣膜超过其平衡位置，腱索在瓣膜上产生张力。这种方法得到了乳头肌破裂、P-R间期延长和数学建模数据的支持。我们提供了一个统一的弦张力，流动减速和旋涡，弦张力作为其他两个适当的功能的必要条件的阀门关闭理论。然而，持续时间较长的心脏舒张和室性期前收缩表明，在没有涡流和血流减速的情况下，瓣膜可以正常关闭。
To examine the mechanisms of mitral valve motion in mid diastole and at closure, we simultaneously measured mitral flow (electromagnetic), valve motion (echo), and atrioventricular pressures (micromanometer). Peak valve excursion (E point) occurs early 46 +/- 7 ms) after opening and always precedes peak flow; therefore, mid-diastolic closing motion (EF slope) is not due to flow deceleration or vortex formation. Large variations in peak flow are accompanied by small variations in valve excursion (coefficient of variation 41 vs. 12%, respectively). We conclude that the valve overshoots its equilibrium position and that the chordae produce tension on the valve during diastole. This approach is supported by data from papillary muscle rupture, prolonged P-R interval, and mathematical modeling. We offer a valve-closure theory unifying chordal tension, flow deceleration, and vortices, with chordal tension as a necessary condition for the proper function of the other two. Nevertheless, prolonged periods of diastasis and ventricular premature contractions indicate that competent valve closure may occur in the absence of vortices and flow deceleration.