实时三维超声心动图观察二尖瓣冗长影响左室流出道血流动力学的应用价值

Application value of left ventricular outflow tract obstruction due to mitralvalve elongation by real-time three-dimensional echocardiography

目的应用实时三维超声心动图(RT-3DE)观察二尖瓣冗长瓣膜立体形态及左室流出道血流动力学改变,分析二尖瓣前叶冗长致左室流出道梗阻的原因。方法选取我院经超声心动图确诊的二尖瓣冗长患者18例(研究组)和正常健康成人23例(对照组),在常规二维超声心动图基础上,应用RT-3DE观察二尖瓣冗长瓣膜立体形态及左室血流动力学改变,测量研究组二尖瓣前叶残余冗长部长度(AMV-eL),比较两组二尖瓣前叶长度(AMV-L)、左室流出道血流速度(LVOT-V)、左室流出道压力阶差(LVOT-P)、室间隔厚度(IVS-D)、左室后壁厚度(LVPW-D)、左室舒张末期内径(LVD-D)、左室收缩末期内径(LVS-D)、二尖瓣血流速度(MV)、左室射血分数(LVEF)及心率。分析二尖瓣冗长形态参数与左室流出道血流动力学参数的相关性。结果两组AMV-L、LVOT-V、LVOT-P、IVS-D、LVPW-D比较,差异均有统计学意义(均P<0.05);两组LVD-D、LVS-D、MV、LVEF、心率比较,差异均无统计学意义。研究组二尖瓣前叶冗长部均出现收缩期前向运动。研究组AMV-eL与AMV-L、LVOT-V、LVOT-P均呈正相关(r=0.925、0.916、0.923,均P<0.05)。结论二尖瓣冗长可致左室流出道梗阻,RT-3DE显示二尖瓣残余冗长部收缩期前向运动是致其梗阻的原因。

Objective To observe the three-dimensional shape of mitral valve elongation and the hemodynamic changes of the left ventricular outflow tract by real time three-dimensional echocardiography(RT-3DE),and to analyze the causes of left ventricular outflow tract dynamic obstruction caused by anterior mitral valve elongation.Methods Eighteen patients with mitral valve elongation confirmed by echocardiography(study group)and 23 normal healthy adults(control group)were selected.On the basis of conventional two-dimensional echocardiography,RT-3DE was used to observe the threedimensional shape and hemodynamic changes of malformed mitral valve,and the length of residual part of anterior mitral valve elongation(AMV-eL),the length of anterior mitral valve(AMV-L),left ventricular outflow velocity(LVOT-V),pressure gradient(LVOT-P),interventricular septal thickness(IVS-D),left ventricular posterior wall thickness(LVPW-D),left ventricular end diastolic diameter(LVD-D),left ventricular end systolic diameter(LVS-D),mitral velocity(MV),left ventricular ejection fraction(LVEF)and heart rate(HR)were measured and compared in the two groups.The correlation between parameters of mitral value elongation and left rentricular outflow tract dynamic parameters.Results There were statistically significant differences in AMV-L,LVOT-V,LVOT-P,IVS-D and LVPW-D between the two groups(all P<0.05),but there were no significant difference in LVD-D,LVS-D,MV,LVEF and HR between the two groups.The systolic anterior motion of anterior mitral valve elongation was found in the study group.The AMV-L of the study group was positively correlated with AMV-eL、LVOT-V and LVOT-P(r=0.925,0.916,0.923,all P<0.05).Conclusion Mitral valve elongation can lead to left ventricular outflow tract obstruction.The systolic anterior motion of anterior mitral valve elongation is the cause of left ventricular outflow tract obstruction.