应用血流向量图研究左心室舒张末期涡流的影响因素

Assessment of factors affecting left ventricular end-diastolic vortex by vector flow mapping

目的应用血流向量图技术(vector flow mapping,VFM)研究左心室舒张末期涡流的影响因素及与充盈方式的关系。方法选择健康志愿者48人、冠心病患者51人、扩张性心肌病患者51人,根据二尖瓣口充盈方式分为正常充盈组29人,松弛受损组85人,假性正常组22人,限制型充盈组14人。心尖左心室长轴观采集左心室彩色多普勒血流图像,VFM技术测量舒张末期左心室涡流面积与流量。结果涡流面积与心率、A峰及瓣环a’速度、左心室大小显著相关,其中A峰速度、心率及左心室舒张长径是涡流面积的独立影响因素(P<0.01)。涡流流量与年龄、心率、A峰速度、左心室大小与功能各指标显著相关,其中A峰速度、心率、左心室收缩短径及舒张长径是涡流流量的独立影响因素(P<0.01)。4组之间涡流面积与流量有显著性差异(均P<0.05),松弛受损组涡流面积显著大于限制型充盈组,正常充盈和松弛受损组流量显著大于假性正常和限制型充盈组。结论舒张末期涡流大小与心率、左心室大小及A峰速度有关,不同充盈方式之间具有显著性差异,提示舒张末期涡流可用于鉴别二尖瓣口充盈的假性正常。

AIM To assess the factors affecting the left ventricular(LV)end-diastolic vortex and the relationships between the vortex and mitral inflow patterns by vector flow mapping(VFM).METHODS Forty-eight healthy volunteers,51 patients with coronary artery disease and 51 patients with dilated cardiomyopathy were divided into 4 groups according to their transmitral flow patterns:29with normal filling,85 with E/A ratio<1,22 with pseudonormal filling,and 14 with restrictive filling.Color Doppler data in LV were recorded in apical long axis view and area and flux of the end-diastolic vortex were measured by VFM.RESULTS In the cohort of all the subjects,the area of the end-diastolic vortex was significantly correlated with heart rate,transmitral A velocity,mitral annulus a’velocity and LV size.Transmitral A velocity,heart rate and LV end-diastolic long diameter were the independent predictors of vortex area(adjusted R2=0.181,P<0.01).Flux of the vortex was significantly correlated with age,heart rate,transmitral A velocity,LV size and parameters of LV function.Transmitral A velocity,heart rate,and LV end-systolic short and end-diastolic long diameters were the independent predictors of vortex flux(adjusted R2=0.575,P<0.01).There were significant differences between the 4 groups in area and flux of the vortex.The group with E/A ratio<1 had a larger vortex area than the group with restrictive filling,and the groups with normal filling and E/A ratio<1 had a larger vortex flux than the groups with pseudonormal and restrictive filling(all P<0.05).CONCLUSION The formation of the end-diastolic vortex is associated with transmitral A velocity,heart rate,and LV size.The difference in the vortex of different LV filling patterns suggests that the end-diastolic vortex can be used to distinguish between a normal and pseudonormal LV filling pattern.