实时三维超声心动图评价心肌梗死后节段容积及其对整体功能的影响

Quantitative assessment of regional volume of left ventricle and their contribution to the global function in patients with myocardial infarction by real-time three-dimensional echocardiography

目的应用实时三维超声（RT-3DE）技术，探讨心肌梗死（MI）后左室各节段心肌在不同血供状况下的功能改变及其对整体心功能的影响。方法采用心脏17节段法进行分组，20例MI患者心肌节段分为三组：心肌梗死节段组（A组）；梗死邻近节段组（B组）和梗死远端节段组（C组）。20例正常人心脏对应MI患者相应节段分为三个对照组。运用RT-3DE技术将MI患者三组心肌节段分别与其对照组节段舒张末期容积（rEDV）、节段收缩末期容积（rESV）、节段射血分数（rEF）、节段局部心搏量与左室心搏量的比值（rgSVRatio）进行比较。结果MI患者A组、B组和C组rESV、rEDV均较正常对照组增大，A组、B组rEF均减低（P〈0．05），C组rEF与正常对照组差异无统计学意义（P〉0．05）；A组rgSVRatio较正常对照组下降、C组rgSVRatio增大（P〈0．05），B组与正常对照组差异无统计学意义（P〉0．05）。结论心肌梗死后，梗死节段和邻近节段容积和收缩功能下降，远端节段容积虽然增大，但在维持整体收缩功能方面起代偿增强作用，实时三维超声心动图可以准确评价心肌梗死后左室整体和节段容积及功能的改变，尤其对心尖各节段的评价更具有优势。

Objective To investigate the change of the left ventricular myocardial segmental volume and function in infarction segments, segments adjacent to infraction area and the segments remote from infraction area and their contribution to the global cardiac function after myocardial infarction（MI） with real time three-dimensional eehocardiography（RT 3DE）. Methods Twenty patients with MI and 20 normal subjects were involved. According to 17 sub-division method which was recommended by American Heart Association,all myocardial segments of the 20 patients with MI were divided into group A（the infarction segment） ,group B（the segments adjacent to the infarction area） and group C（the segments remote from the infraction area）. The myocardial segments of 20 normal patients were divided into three paired groups corresponding to the three MI groups according to one-by one matching rule. RT 3DE was performed on both sets of subjects, in which the regional end-diastolic volumes （rEDV）, regional end-systolic volumes （rESV） ,regional ejections farctions （rEF） were assessed. And also, the ratio of regional stroke volume to global stroke volume（rgSVRatio） was used to evaluate the contribution of regional myocardium to global function. Results The basic clinic parameters between MI patients and normal controls were not significantly different,compared with control group, rESV, rEDV of group A, group B and group C were enlarged and rEF of group A and group B were decreased （ P 〈0.05）. And as for the rgSVRatio, group A was lower than that of the control group, while the rgSVRatio of group C was greater （ P 〈 0.05）. Conclusions The global and segmental cardiac function in patients with MI were reduced, however, the ejection contribution of the segments remote from the infarction region was enhanced in MI patients. RT- 3DE can precisely evaluate the geometrical, functional, and volume changes globally and regionally in MI patients, especially for apical parts assessment.