应用血流向量图研究左心室舒张末期涡流的影响因素

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。

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

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: 29 with 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.