| Objective:Hypertrophic cardiomyopathy（HCM）is a genetic disease with various clinical phenotypes.Its basic feature is asymmetric hypertrophy of left ventricular wall.Because its definition standard is mainly based on left heart,the function of right heart and left atrium has been neglected for a long time.The purpose of this study is to comprehensively evaluate the difference of cardiac function among left,right ventricle and left atria in patients with hypertrophic cardiomyopathy by magnetic resonance multiparameters.To explore the relationship between left ventricular myocardial fibrosis and myocardial strain,and explore the predictive value of left atrial myocardial strain parameters for atrial fibrillation in HCM patients,so as to make a more comprehensive risk assessment of the course of the disease,better help the clinical diagnosis and treatment of patients with hypertrophic cardiomyopathy,and improve the long-term prognosis.Materials and methods:In this study,48 patients with hypertrophic cardiomyopathy（including22 obstructive patients,16 non-obstructive patients and 10 apical hypertrophic patients）and 27 volunteers were included in the study.All the above-mentioned personnel underwent cardiac magnetic resonance examination,and the obtained images were imported into post-processing analysis software（CVI42,Canada）.After sketching,the software automatically calculates the conventional cardiac parameters（including left ventricular diastolic/systolic volume index LVEDVI/LVESVI,right ventricular diastolic/systolic volume index RVEDVII/RVESVI,left ventricular stroke output LVSV,left/right ventricular ejection fraction LVEF/RVEF,left atrium maximum/small volume LAVmax/LAVmin,etc.）and myocardial strain parameters(including left/right ventricular overall longitudinal strain LVGLS/ RVGLS,global circumferential strain LVGCS/ RVGCS,global radial strain LVGRS/ RVGRS,total strain Es、active strain Ea 、 passive strain Ee of left atrial,longitudinal 、circumferential and radial strain of 16 segments of left ventricle（768segments in total）,the late gadolinium enhancement volume LGE 、the late gadolinium enhancement volume ratio LGE%、T1-mapping and ECV of the whole left ventricle and 16 myocardial segments,and then all data were processed by SPSS software.Results:The values of T1 and ECV in patients with obstructive hypertrophic cardiomyopathy group and non-obstructive hypertrophic cardiomyopathy group respectively were [（506.35±42.73）vs（473.11±28.89）,（35.30±35.50）vs（38.78±3.56）],and the differences were statistically significant（P<0.05）.The GLS、GCS and GRS of left ventricular myocardium in the three subtypes of hypertrophic cardiomyopathy group were significantly lower than those in the control group,and the differences were statistically significant（P<0.05）.The left atrial minimum volume LAVmin and the left atrial maximum volume LAVmax in the three subtypes of hypertrophic cardiomyopathy group were significantly higher than those in the control group,and the differences were statistically significant（P<0.05）.The total strain Es,passive strain Ee and active strain Ea of left atrium in the three subtypes of hypertrophic cardiomyopathy group were significantly lower than those in the control group,and the differences were statistically significant（P<0.05）.Spearman correlation analysis showed that the longitudinal value LS of segmental myocardium was negatively correlated with the ratio of delayed enhancement to LGE% of myocardium（r=-0.305,P<0.05）.The GLS,GCS and GRS of left ventricular are significantly positively correlated with the corresponding right ventricular axial strain（r=-0.439,P < 0.05,r=-0.709,P < 0.00,r=0.711,P < 0.00）.Logistic regression analysis showed that the total strain value Es of left atrium was independently correlated with atrial fibrillation（r=-0.305,P<0.05）.Conclusion:1.The left atrial and right ventricular functions of patients with hypertrophic cardiomyopathy will be damaged,and the damage of right ventricle may be later than that of left atrium.Magnetic resonance imaging can evaluate the course of hypertrophic cardiomyopathy,and the decrease of left atrial myocardial strain can predict the occurrence of arrhythmia.2.The decrease of left ventricular longitudinal strain in patients with hypertrophic cardiomyopathy is related to delayed enhancement,which can be used as a potential independent marker to evaluate the severity of myocardial fibrosis in patients with contraindication of contrast agent.3.Left ventricular outflow tract obstruction will aggravate the degree of myocardial diffuse fibrosis in hypertrophic cardiomyopathy. |
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