Study Of Left Ventricular Global Function And Myocardial Fibrosis In Patients With Primary Dilated Cardiomyopathy By Cardiac Magnetic Resonance Imaging

Background: Dilated cardiomyopathy(DCM)is a common organic heart disease.The main manifestation of DCM is that the enlargement of the cardiac cavity is obviously accompanied by different degrees of cardiac relaxation dysfunction,which can easily lead to sudden death.Therefore,it is of great clinical significance to accurately evaluate the cardiac function and tissue characteristics of DCM.At present,echocardiographic screening is the most common method of DCM imaging.In recent years,with the rapid development of magnetic resonance technology,besides the advantages of non-radiation,multi-sequence parameters and high repeatability of traditional magnetic resonance,the heart can also collect data of structure,shape,function,myocardial activity(perfusion and delayed enhancement)of heart and blood vessels.Now it has been widely used in clinical diagnosis,especially in the diagnosis of myocardial fibrosis by delayed enhancement of CMR,which can play a very good guiding role in the treatment of clinical sequencing.At present,many imaging methods can obtain the corresponding cardiac function indicators,but because of the different imaging principles and operation techniques,the specific results are not consistent.The technology development of CMR abroad is approaching maturity,and there are many applications in China,but the clinical application of DCM is not very extensive at present.Objective:To investigate the value of 1.5T cardiac magnetic resonance imaging in the study of left ventricular global function and myocardial fibrosis in patients with primary dilated cardiomyopathy.Methods: 27 DCM patients and 27 healthy volunteers were collected.All subjects underwent 1.5 TCMR plain scan and enhancement examination to obtain left ventricular plain film images and delayed enhancement(DE-MRI)images.The leftventricular function indexes(standardization of body surface area)and myocardial delayed enhancement information were obtained.Functional parameters included left ventricular end-systolic volume(LVESV),left ventricular end-diastolic volume(LVEDV),left ventricular ejection fraction(LVEF),left ventricular peak ejection rate(LVPER),left ventricular peak filling rate(LVPFR),left ventricular myocardial mass(LVMM),left atrial anterior and posterior diameter(LAAPD),left ventricular end-diastolic length(LVLD),left ventricular end-diastolic maximum transverse diameter(LVEDTDmax),left ventricular end-systolic maximum transverse diameter(LVESTDmax)and ventricular mass.Interval Thickness Diameter(IVSTD).To compare the difference of various values between DCM experimental group and healthy group,and to compare the difference of some conventional cardiac function indexes between CMR group and ultrasound group.In the DCM experimental group,the above indicators were divided into two subgroups according to whether or not delayed enhancement(DE-MRI): DE-MRI(+)group and DE-MRI(-)group,and the numerical differences between the two groups were compared.Results: 1.There was no significant difference in some routine cardiac function indexes between CMR group and ultrasound group.2.The indexes of LVEDV,LVESV,LVMM,LAAPD,LVLD,LVEDTDmax and LVESTDmax in DCM experimental group were significantly higher than those in healthy control group,while the indexes of IVSTD,LVEF,LVPER and LVPFR in DCM experimental group were lower than those in healthy control group,and all had statistical differences.3.The indexes of LVMM and LVESV in DE-MRI(+)group were higher than those in DE-MRI(-)group,and the indexes of LVEF in DE-MRI(+)group were lower than those in DE-MRI(-)group,and all had statistical differences.There was no difference among the other groups.3.In DCM group,17cases(17/27,63%)had delayed myocardial enhancement,and 153 segments had delayed myocardial enhancement.101 segments(101/153,66.01%)between the muscles had significant enhancement characteristics,and 12 cases(70.58%)were mainly located in the interventricular septal wall.Conclusion: 1.1.5 TCMR canevaluate the cardiac function and myocardial fibrosis of DCM well: the left ventricular global function of DCM is significantly reduced,accompanied by myocardial fibrosis with significant distribution between the septal wall muscles;2.LVMM can roughly evaluate the myocardial fibrosis of DCM(MF).