超声血流向量成像评价糖尿病前期左心室舒张期流场状态

An initial study of left intra-ventricular diastolic fluid dynamics in pre-diabetics using vector flow mapping

目的 应用超声血流向量成像（vector flow mapping,VFM）技术评价糖尿病前期患者左心室腔内血液流场变化特征及流体力学状态,探讨糖尿病早期血流动力学改变的敏感指标.方法 随机选取2型糖尿病患者44例、糖尿病前期患者28例、健康对照33例,采集3个完整心动周期标准心尖四腔观彩色多普勒实时动态图像.测量左心室舒张功能参数后,应用专用软件对所采集图像进行处理,获取并对比分析各组左心室舒张期心腔内基底、乳头肌和心尖水平血流速度向量峰值、速度阶差（△V）、压力梯度（△P）、血流量以及心腔内涡流强度（vortex intensity,Ⅵ）、涡流半径（vortex radius,VR）、涡流面积（vortex area,VA）等参数.比较各组测值差异并对左心室舒张功能参数和流场参数进行相关分析.结果 ①常规舒张功能测量：糖尿病组E/A、e/a较正常组、糖尿病前期组减小,差异具有统计学意义（P＜0.01）；糖尿病前期组E/A、e/a与正常组比较,差异无统计学意义（P＞0.05）；糖尿病前期组、糖尿病组E/e与正常对照组比较,差异无统计学意义（P＞0.05）.②速度压力场观测：糖尿病前期组、糖尿病组较正常对照组左心室舒张期基底水平血流速度峰值、△V、△P减小（P＜0.01）,糖尿病前期组与糖尿病组比较,差异无统计学意义（P＞0.05）.③流量观测：两病例组左心室舒张期基底水平正向血流量减少（P＜0.01）,糖尿病组与糖尿病前期组比较差异无统计学意义（P＞0.05）.④涡量场观测：两病例组Ⅵ减弱（P＜0.01）,糖尿病组与糖尿病前期组比较差异无统计学意义（P＞0.05）；两病例组VR、VA较正常对照组呈递增趋势,但差异无统计学意义（P ＞0.05）.⑤相关性分析：各组常规舒张功能参数与左心室流场参数无相关性.结论 糖尿病前期已存在与2型糖尿病类似的左心室流体力学异常状态.应用VFM技术可直观定量评价糖尿病前期左心室舒张期血液流场的变化特征,有望为临床提供一种能够早期发现糖尿病患者心脏血流动力学损害的新方法.

Objective To evaluate left intra-ventricular diastolic blood flow patterns and fluid dynamics in pre diabetics using vector flow mapping（VFM）,and to explore the value of left intra-ventricular hydromechanics characteristics assessment of intracardiac flow by VFM with more sensitive indexes.Methods Forty four patients with type 2 diabetes,twenty-eight pre-diabetes patients and thirty-three normal volunteers underwent VFM to determine the left ventricular（LV） diastolic blood flow patterns and fluid dynamics.The two-dimensional color Doppler flow images data were acquired in standerd apical fourchamber view during 3 complete cardiac cycles.These images were analyzed using a dedicated off-line workstation.At different level （mitral annulus,papillary muscl and apex level）,the diastole blood flow parameters of LV including flow velocity and volume,velocity gradients （△V）,pressure gradients （△P）,diastole flow volume,vortex intensity （ Ⅵ）,vortex area （ VA）,vortex radius （VA） were derived.Thedifferences of the above parameters were compared among the three groups.The correlationship between diastolic function parameters and LV hydromechanics indexes were analyzed.Results ① Compared to normal group and pre-diabetics group,the LV diastolic function parameters E/A and e/a in diabetics group were lower（ P 〈0.01）,with no differences for E/e（ P 〉0.05）.There were no significant diffrences of these indices between diabetics group and pre-diabetics group（ P 〉0.05）.②）Compared to normal group,the intraventricular peak flow velocity at basal level,△V and △P in diabetics group and pre-diabetics group were lower（ P 〈0.01）,but there were no significant differences of these indices between diabetics group and prediabetics group（ P 〉 0.05）.③Compared to normal group,the diastolic positive volume at basal level in diabetics group and pre-diabetics group was lower （ P 〈0.01 ）,but there was no significant differences of these indices between diabetics group and pre-diabetics group （ P 〉 0.05）.④ Compared to the normal group,the Ⅵ in diabetics and pre-diabetics group was decreased,but there were no significant differences of these indices between diabetics group and pre-diabetics group（ P 〉0.05）.The VA and VR in diabetics and pre-diabetics group were increased,but there were no significant differences of these indices between diabetics group and pre-diabetics group （ P 〉 0.05）.⑤ There were no correlationship between diastolic function parameters and LV hydromechanics indexes.Conclusions There is the same LV diastolic blood flow patterns and fluid dynamics existed in pre-diabetics as diabetics.VFM could be used as a new methods to demonstrate the early left intra-ventricular fluid dynamics damages in pre-diabetics patients.