Cardiac MR Tissue Tracking For Quantitative Assessment Of Right Ventricular Strain In Hypertrophic Cardiomyopathy

Objective: To explore the feasibility of cardiac MR tissue tracking(CMR-TT)in assessing right ventricular(RV)function and strain of hypertrophic cardiomyopathy(HCM)patients and the correlation of RV strain and left ventricular strain.Methods: 32 HCM patients(HCM group)and 32 healthy volunteers(control group)were performed by 3.0T SSFP film sequence scanning in this study.Left ventricular function and the strain parameters of two ventricles were measured by cmr-tt technology from CVI42 post-processing software of Canada.Clinical characteristics and basic parameters of left ventricular function(gender,age,LVEF,LVEDV,LVESV,LVM)of the HCM group and the control group were collected.Counting data were analyzed by independent sample chi-square test,and measurement data were expressed by `x±s.The strain of the two ventricles is divided into global strain and segmental strain(strain at the base,middle and apex of the heart)by location,and circumferential strain,radial strain and longitudinal strain by direction.Independent sample t test was used for pairwise comparison of left and right ventricular strain parameters between the two groups.Pearson analysis was used to analyze the correlation between right ventricular strain and left ventricular strain in the HCM group.Results: Left ventricular mass(LVM)of HCM group was significantly higher than control group(t=1.41,P<0.01),and left ventricular function parameters including left ventricular ejection fraction(LVEF),left ventricular end-diastolic volume,left ventricular end-systolic volume had no difference between HCM group and control group(all P>0.05).In HCM group,the global radial strain(GRS),global circumferential strain(GCS)and global longitudinal strain(GLS)in left ventricle and right ventricle were significant lower than those in the control group(all P<0.01).In addition to the basal radial strain of both ventricles,the segment local strain in the HCM group was reduced compared with the control group(P<0.01).The GRS of RV was positively correlated to left ventricle GRS(r=0.375,p=0.034)and was negatively correlated to left ventricle GLS(r=-0.466,p=0.007);RV global GCS was positively correlated to left ventricle GCS,GLS(r=0.531,0.462,P=0.002,0.008).Conclusion: RV segment strain and global strain can respond right ventricular systolic function in HCM sensitively.Both left and right ventricular systolic function of HCM patients has been impaired before LVEF reduced.And the systolic dysfunction between RV and LV has a certain degree of correlation.