血流向量图——评估房间隔缺损分流量的新方法

A novel approach to assess the shunt-flow volume of atrial septal defect

目的应用超声血流向量图(VFM)技术,分析房间隔缺损的分流量及其影响因素。方法选取20例Ⅱ孔型房间隔缺损患者为观察对象,应用VFM技术获得心腔内的血流速度向量和流线图,采用DSA-RS1软件测量房间隔缺损最大径处的分流量,分析分流量与肺循环血流量与体循环血流量的比值(Qp/Qs)、房间隔缺损最大直径、左、右心房的压力及差值的相关性。结果通过VFM获得的房间隔缺损分流量与Qp/Qs呈正相关(r=0.93,P<0.01)。分流量受房间隔缺损大小影响最大(r=0.95,P<0.05),即房间隔缺损越大,分流量越大。房间隔缺损分流量越大,左心房的收缩压越低(r=-0.61,P<0.05)、左、右心房间收缩压的压力差越小(r=-0.57,P<0.05)。房间隔缺损的分流量与右心房收缩压、左、右心房间的舒张压差和平均压差均无相关性(P均>0.05)。结论 VFM能够真实地反映心腔内血流动力学的变化。应用VFM技术可直接测量房间隔缺损的分流量,为临床提供有价值的血流动力学参数。

Objective To assess the shunt-flow volume in the atrial septal defect（ASD）patients and the influence factors of it with vector flow mapping（VFM）technique.Methods Twenty ostium secundum ASD patients were enrolled.VFM technique was used to obtain the velocity distribution images and the shunt flow volume when placing the sample line at the maximum diameter of the defect measured with DSA-RS1 software.The correlation between shunt-flow volume and ratio of pulmonary flow to systemic blood flow（Qp/Qs）,the maximum diameter of the defect,left and right atrial pressure and their difference value were analyzed.Results The shunt flow volume acquired with VFM was correlated well with Qp/Qs（r=0.93,P0.01）.Magnitude of shunting was determined by the size of the defect（r=0.95,P0.05）.The shunt-flow volume negatively correlated with left atrial systolic pressure（r=-0.61,P0.05）and the difference of systolic pressure between left and right atria（r=-0.57,P0.05）.No correlation was found among shunt flow volume and right atrial systolic pressure,the difference of diastolic or mean pressure between two atria（all P0.05）.Conclusion Vector flow mapping（VFM）is an ideal method to measure the shunting of ASD and evaluate right chamber flow dynamics.