Tsakiris A G, Gordon D A, Mathieu Y, Irving L
J Appl Physiol. 1975 Sep;39(3):359-66. doi: 10.1152/jappl.1975.39.3.359.
Motion and position of both mitral leaflets were studied in five normal dogs 1-11 wk after radiopaque markers were sutured on the valve cusps and on the mitral annulus. Cinefluorograms and cineangiograms (100-120 frames/s) of left atrium and left ventricle were used to study cusp motion and intraventricular flow patterns, and to detect mitral regurgitation during sinus rhythm (42-184 beats/min) and during isolated atrial or ventricular contractions. Time-motion of both leaflets was similar throughout diastole with the exception of delayed posterior cusp opening. Peak opening and closing speeds, opening and closing times, and time of complete closure, measured from the Q wave of the ECG, were not significantly affected by the variations in heart rate. Diastolic leaflet closure began immediately after opening, while the ventricular cavity was small, and was caused by flow eddies behind the cusps. Isolated ventricular contractions closed the valve leaflets completely and symmetric valve closure was ensured by the different rates of leaflet edge approximation. In contrast, atrial closure was slow, partial, and of very short duration.
在五只正常犬的二尖瓣叶瓣尖和二尖瓣环上缝合不透射线标记物后1至11周，研究了两个二尖瓣叶的运动和位置。利用左心房和左心室的电影荧光造影和电影血管造影（100 - 120帧/秒）来研究瓣尖运动和心室内血流模式，并检测窦性心律（42 - 184次/分钟）期间以及单独心房或心室收缩期间的二尖瓣反流。除了后瓣叶开放延迟外，两个瓣叶在整个舒张期的时间 - 运动相似。从心电图的Q波测量的最大开放和关闭速度、开放和关闭时间以及完全关闭时间，不受心率变化的显著影响。舒张期瓣叶在开放后立即关闭，此时心室腔较小，这是由瓣叶后方的血流漩涡引起的。单独的心室收缩可使瓣膜完全关闭，并且通过瓣叶边缘接近速度的不同确保瓣膜对称关闭。相比之下，心房关闭缓慢、不完全且持续时间很短。
