实时三维超声心动图测量左心室容量与射血分数的实验研究

Experimental study of real-time three-dimensional echocardiography in quantifying left ventricular volume and ejection fraction

目的 评价实时三维超声心动图 (RT 3DE)测量左心室容量与射血分数的准确性。方法 对 10只杂种犬结扎冠状动脉左前降支 (LAD)建立急性心肌梗死模型 ,应用RT 3DE以Fullvolume方式采集左心室图像 ,分别采用 2、4、8平面法脱机测量左心室的收缩末期容量 (LVEDV )、舒张末期容量(LVESV)、心搏量 (SV)和射血分数 (LVEF) ,并与二维双平面Simpson法 ( 2 DE)测值进行比较。测量离体心脏左心室的实际容量 (TV)并与 2 DE、RT 3DE的LVEDV测值进行比较。结果 ①RT 3DE 2、4、8平面法测量的LVEDV、LVESV、SV高度相关 (r =0 .90～ 0 .99) ,2平面法各项测值低于 4、8平面法测值 ,差异有显著性意义 (P <0 .0 5 ) ,而 4、8平面法间各测值差异无显著性意义 (P >0 .0 5 ) ;②RT 3DE 2、4、8平面法测量的LVEDV、LVESV、SV与 2 DE对应的测值均高度相关 (r =0 .92～ 0 .99) ,但 2 DE测值低于RT 3DE 4、8平面法测值 (P <0 .0 5 ) ,而与RT 3DE 2平面法测值间差异无显著性意义 (P >0 .0 5 ) ;③RT 3DE 2、4、8平面法与 2 DE测量的LVEF高度相关 ( r =0 .90～ 0 .99) ,各测值间差异无显著性意义 (P >0 .0 5 ) ;④ 2 DE、RT 3DE 2、4、8平面法测量的LVEDV与TV的测值高度相关 (r =0 .80～ 0 .88) ,但 2 DE与RT 3DE

Objective To assess the accuracy of real-time three-dimensional echocardiography(RT-3DE) for measuring left ventricular volume and ejection fraction.Methods Acute myocardial infarction models were established in 10 dogs by occluding left anterior descending coronary arteries for 60 minutes and studied with RT-3DE full volume imaging and two-dimensional echocardiography(2-DE). Left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), stroke volume (SV) and left ventricular ejection fraction (LVEF) were measured off-line using 2-, 4- and 8-plane methods of RT-3DE analysis software, and compared with 2-DE derived parameters which were obtained by biplane Simpson's method. At the end of the experiment, the hearts were excised and the true left ventricular volumes (TV) were evaluated by injecting water and served as a reference standard.Results ① There existed high correlations between LVEDV, LVESV, SV measured by RT-3DE(r= 0.90- 0.99), but parameters derived from 2-plane method were significantly lower than those from 4- and 8-plane methods (P< 0.05), and no differences were found between those from 4- and 8-plane methods(P> 0.05). ② LVEDV, LVESV, SV obtained from RT-3DE correlated well with those from 2-DE(r= 0.92- 0.99), but 2-DE-measured indice were significantly lower than those from RT-3DE 4- and 8-plane methods(P< 0.05),while had no significance with those from 2-plane method(P> 0.05). ③ LVEF measured by RT-3DE in the three plane methods correlated well with that of 2-DE measurements(r= 0.90- 0.99), but no significant differences existed between them(P> 0.05). ④ High correlations were also found between 2-DE, RT-3DE derived LVEDV and TV (r= 0.80- 0.88), but 2-DE and RT-3DE 2-plane methods underestimated TV significantly (P< 0.05). Conclusions RT-3DE shows a high accuracy in quantifying left ventricular volume and ejection fraction, and RT-3DE 4- and 8-plane methods are superior to 2-DE and RT-3DE 2-plane methods in evaluating left ventricular volume.