Kim W Y, Walker P G, Pedersen E M, Poulsen J K, Oyre S, Houlind K, Yoganathan A P
Department of Thoracic and Cardiovascular Surgery, Skejby Sygehus, Aarhus University Hospital, Denmark.
J Am Coll Cardiol. 1995 Jul;26(1):224-38. doi: 10.1016/0735-1097(95)00141-l.
Magnetic resonance velocity mapping was used to investigate the hypothesis of a vortex motion within the left ventricle interacting with mitral valve motion and inflow velocity.
In vitro flow visualization studies have suggested the presence of a large anterior vortex inside the left ventricle during mitral inflow. However, to our knowledge the occurrence of this phenomenon has not been demonstrated in the human left ventricle.
Magnetic resonance velocity mapping was performed in 26 healthy volunteers using a flow-adjusted gradient sequence for three-dimensional flow velocity acquisition in the long-axis plane of the left ventricle. By computer processing, the flow vectors in the left ventricle were visualized and animated dynamically.
The early diastolic mitral inflow was apically directed, and a large counterclockwise anterior vortex was created within the left ventricle shortly after the onset of the mid-diastolic semiclosure of the anterior mitral leaflet. During mid-diastolic diastasis, mitral inflow ceased until the flow accelerated again at atrial systole. The final closure of the mitral valve was preceded by a smaller vortex seen at the tips of the mitral leaflets. At systolic ejection, all flow vectors were directed toward the left ventricular outflow tract. The anterior vortex had a radius of 1.62 +/- 0.24 cm (mean +/- SD), and the average angular velocity (i.e., the rotation of an element about the center of the vortex within the central core) was 30.08 +/- 9.98 radians/s. The maximal kinetic energy of the anterior vortex was 4.3 x 10(-4) +/- 7.1 x 10(-5) J.
The hypothesis of a diastolic vortex formation in the human left ventricle was confirmed, and its close temporal relation to the motion of the anterior mitral leaflet was demonstrated.
采用磁共振速度成像技术验证左心室内的涡旋运动与二尖瓣运动及流入速度相互作用的假说。
体外血流可视化研究提示二尖瓣流入期间左心室内存在一个大的前向涡旋。然而，据我们所知，这种现象在人类左心室中尚未得到证实。
对26名健康志愿者进行磁共振速度成像，采用流量调整梯度序列在左心室长轴平面采集三维流速。通过计算机处理，左心室内的血流矢量得以可视化并动态显示。
舒张早期二尖瓣流入指向心尖，在前叶舒张中期半关闭开始后不久，左心室内形成一个大的逆时针前向涡旋。在舒张中期静止期，二尖瓣流入停止，直到心房收缩期血流再次加速。二尖瓣最终关闭之前，在二尖瓣叶尖端可见一个较小的涡旋。在收缩期射血时，所有血流矢量均指向左心室流出道。前向涡旋半径为1.62±0.24 cm（均值±标准差），平均角速度（即中心核内某一元素绕涡旋中心的旋转）为30.08±9.98弧度/秒。前向涡旋的最大动能为4.3×10⁻⁴±7.1×10⁻⁵ J。
人类左心室舒张期形成涡旋的假说得到证实，并证明其与二尖瓣前叶运动存在密切的时间关系。
