The Clinical Research Of Left Atrial Volume In Patients With Acute Myocardial Infarction Using Real-time Three Dimensional Echocardiography

Background: It is of great significance for doctors to choose preoperative selectionand to evaluate postoperative treatment, in order to accurately detect of cardiacfunction in patients with acute myocardial infarction. Currently, people pay moreattention on left ventricular systolic function. However, left ventricular diastolicfunction plays an important role in left ventricular systolic function, and the leftventricular diastolic dysfunction in patients with myocardial infarction usuallyappears earlier than systolic dysfunction. Therefore, early and accurate detection andimprove the diastolic function in patients with acute myocardial infarction is of greatsignificance to reduce mortality in patients with myocardial infarction. Left atrialvolume indexes’ change have important effects on left ventricular diastolic function,when cardiac appears diastolic dysfunction, the left atrial volume increases. The sizeof the left atrial and the change of the form can sensitively reflect the left ventriculardiastolic function. Real-time three-dimensional echocardiography (real-time threedimensional echocardiography, RT3DE) observed each position of the heart, theinstant full volume of the heart with three-dimensional database structure, thusanalysis of morphology and function of the size of the heart, is the evaluation of leftatrial volume and function，is more accurate, rapid, noninvasive examination method,and with the gold standard in the heart of the nuclear magnetic correlation ishigher[1]. Brain natriuretic peptide (brain natriuretic peptide, BNP) secreted by the ventricularmuscle cells, reflect the left ventricular end-diastolic pressure, and the left ventricularend-diastolic pressure is the gold standard to evaluate left ventricular diastolicfunction, the concentration of plasma BNP increases as left ventricular end-diastolicpressure rises, so the use of plasma BNP concentration can reflect the left ventriculardiastolic function. At present there are many reasearches about the BNP in heartfailure, but the conclusion is much more consistent.2012European society ofcardiology guidelines for heart failure points out that if the BNP <100pg/ml, can ruleout acute heart failure.In this paper, on the basis of the BNP’s normal reference range (0-100pg/ml) intogroups, divided into elevated BNP group and normal group, or heart failure group andthe control group. Using RT3DE technology test the left atrial volume parameter ofthe two groups, and compare the difference between the two groups with the left atrialvolume parameters, and analysis the correlation between the BNP and left atrialvolume index parameters of all patients, and also analysis the correlation betweenE/E’ and left atrial volume index parameters of all patients，points out that the threedimensional left atrial volume parameters can also be good assessment of leftventricular diastolic function in patients with acute myocardial infarction.Methods: Check the57patients who were diagnosed as acute myocardialinfarction in our hospital from2012to2013with RT3DE. Group the patientsaccording to the plasma BNP,28patients were divided into cases group and29patients divided into control group, the cases of plasma BNP>100pg/ml, the controlof plasma BNP <100pg/ml. Collected everyone’s standard four-chamber view by fullvolume3D model images and process them offline with QLAB software process.Measuring parameters include: left atrial end diastolic volume (LAEDV), left atrialend systolic volume (LAESV), left ventricular presystolic volume (LAVp), leftventricular ejection fraction (LAEF), left atrial passive emptying fraction (LAPEF),LAPEF=(LAEDV-LAVp)/LAEDV, reflecting the left atrial conduit function; Leftatrial active emptying fraction (LAAEF), LAAEF=(LAVp-LAESV)/LAVp, reflectthe left ventricular pump function. Results: The case group compared with control group left atrial volume parameters:There are significant differences between the two groups in LAESV, LAVp andLAEF(P <0.01). There are differences between the two groups of LAEDV, LAAEFand LAPEF difference (P <0.05). Cases of LAESV、LAVp significantly greater thanthe control group. Cases of LAEDV is greater than the control group. Cases of LAEFsignificantly less than the control group. LAAEF and LAPEF in cases group were lessthan the control group.Pearson correlation coefficient analysis: the LAESV and BNP has significantpositive correlation，the correlation coefficient of0.73. The LAVp and BNP hassignificant positive correlation，the correlation coefficient of0.55. The LAEDV andBNP has significant positive correlation，the correlation coefficient of0.42. TheLAAEF and BNP has significant negative correlation，the correlation coefficient is0.50. The LAPEF and BNP has significant negative correlation，the correlationcoefficient is0.26. The LAESV and E/E’ has significant positive correlation，thecorrelation coefficient of0.67. The LAVp and E/E’ has significant positivecorrelation，the correlation coefficient of0.64. The LAEDV and E/E’ has significantpositive correlation，the correlation coefficient of0.58.Conclusion:1、RT3DE detected left atrial volume parameters and function is quick，accurate andreliable.2、Left atrial volume parameters and function tested by RT3DE can better reflectthe left ventricular diastolic function in patients with acute myocardial infarction，among them，the LAESV evaluating left ventricular diastolic function is moresensitive and reliable.