实时三维超声心动图测量急性心肌梗死左心室容积与射血分数最佳切面的研究

Study of optimal cutting planes for the measurement of left ventricular volume and function by real-time three- dimensional echocardiography in acute myocardial infarction

目的探讨实时三维超声心动图（RT-3DE）测量急性心肌梗死左心室容积与射血分数的最佳切面。方法对14条杂种犬急性心肌梗死动物模型进行二维（2DE）和RT-3DE检查，分别应用2DE和RT-3DE的2-平面法、4-平面法和8-平面法测量左心室舒张末期容积（EDV）、收缩末期容积（ESV）、每搏输出量（SV）和射血分数（EF），用注射盐水法测量离体心脏左心室容积作为参照容积，采用Bland和Ahman方法进行一致性分析。结果2DE和RT-3DE的2-平面法、4-平面法测量的EDV、ESV、SV与RT-3DE8-平面法的测量结果高度相关（r=0．84～0．99），2DE、RT-3DE2-平面法测值显著低于RT-3DE8-平面法测值（P〈0．01），而RT-3DE4-平面法与8-平面法测值间差异无统计学意义（P〉0．1）5）。2DE、RT-3DE2-平面法及4-平面法测量的EF与RT-3DE8-平面法测量结果高度相关（r=0．82～0．98），与RT-3DE8-平面法测量的EF值间差异无统计学意义（P〉O．05）。2DE、RT-3DE2-平面法、4-平面法测量的EDV与参照容积测量结果高度相关（r=0．84，0．92，0．94，0．97），RT-3DE 4-平面法、8-平面法的EDV测值与参照容积间差异无统计学意义（P〉0．05），但2DE、RT-3DE2-平面法的EDV测值显著低估参照容积（P〈0．01）。RT-3DE4-平面法、8-平面法测量的EDV与参照容积间的一致性明显高于2DE、RT-3DE2-平面法。RT-3DE4-平面法测量的可重复性优于2DE。结论RT-3DE在测量急性心肌梗死左心室容积和射血分数中具有较高的准确性和可重复性，其中RT-3DE4-平面法是既准确又省时的最佳测量切面。

Objective To derive the optimal cutting planes of real-time three-dimensional echocardiography （RT-3DE） for measuring left ventricular volume and ejection fraction（EF） in the presence of left ventricular regional wall motion abnormalities. Methods Fourteen open-chest dogs were studied with two-dimensional echocardiography （2DE） and RT-3DE full volume imaging after left anterior descending coronary arteries were occluded for 90 minutes. Left ventricular end diastolic volume （EDV）, end systolic volume （ESV）,stroke volume （SV） and EF were measured off-line with 2DE and RT-3DE （2-,4- and 8- plane） methods. The autopsy left ventricular volume was estimated by the volume of saline solution injected into the excised heart and served as the reference volume （Ref V） for comparison with EDV measured by 2DE and RT-3DE. Agreement analysis was performed according to the method of Bland and Airman. Results There were excellent correlations between 2DE, RT-3DE 2-plane and 4-plane methods on one hand,and RT- 3DE 8-plane method on the other in the measurements of EDV, ESV and SV （ r = 0. 84-0. 99 ）. However, 2DE and RT-3DE 2-plane measurements significantly underestimated RT-3DE 8-plane（ P 〈0. 01 ） whereas no significant differences between RT-3DE 4-plane and 8-plane were found in terms of EDV, ESV and SV measurements （ P 〉0.05）. The values of EF determined by 2DE, RT-3DE 2-plane and 4-plane methods correlated highly with that by RT-3DE 8-plane（ r = 0.82-0.98） and there was no significant difference between the two measurements （ P 〉0.05）. EDV values determined by 2DE, RT-3DE 2-plane,4-plane and 8-plane correlated highly with Ref V （ r = 0.84, r = 0.92, r = 0.94 and r = 0. 97, respectively） and there was no significant difference between Ref V and EDV by RT-3DE 4-plane and 8-plane. In contrast, EDV measured by 2DE and RT-3DE 2-plane methods underestimated Ref V significantly （ P 〈0.01 ）. Conclusions RT-3DE allows reliable and reproducible measurement of left ventricular volume and EF even in the presence of regional wall motion abnormalities and RT-3DE 4-plane method is the best choice for accurate and timesaving quantification of left ventricular volume and function.