Difference Of Myocardial Strain And LGE In Different Subtypes Of Hypertrophic Cardiomyopathy

Objective Use cardiovascular magnetic resonance tissue tracking(CMR-TT)and late gadolinium enhancement(LGE)to explore left ventricular apical hypertrophic cardiomyopathy,mid-ventricular hypertrophic cardiomyopathy and basal hypertrophic cardiomyopathy imaging features.Material and Methods A total of 102 patients from September 2014 to September 2018 who was diagnosis with HCM underwent cardiovascular magnetic resonance(CMR)and echocardiography.Thirty-six patients were classified as ApHCM,twenty-eight patients and thirty-eight patients were classified as MVHCM and BHCM,respectively.On CMR,the amount and proportion of late gadolinium enhancement(LGE)as well as global radial strain(GRS),global circumferential strain(GCS)and global longitudinal strain(GLS)automatically were evaluated.Echocardiographic evaluations included left ventricular volumetric parameters diastolic function.Result A total of 102 patients were included.The patients with apical hypertrophy,middle ventricular hypertrophy,and basal hypertrophy cardiomyopathy were 36,28,and 38,respectively.①Basal hypertrophic cardiomyopathy group showed more severe insufficiency[NYHA Ⅱ-Ⅲgrade and NT-proBNP level was singnificantly higher than the other two group(P<0.01)].②The E/e’ value of the BHCM group increased significantly,and the ratio of the ApHCM group and MVHCM group was[(17.03±4.78)vs(11.36±4.25),(17.03±4.78)vs(11.74±0.583.01)(all P<0.01)].③The ratio of LGE to left ventricular myocardium of the ApHCM,MVHCM and BHCM was(6.06±2.1)%、(13.59±5.91)%、(15.21±9.79)%;the total LGE volumes were(6.427±2.31)ml、(14.47±7.87)ml、(15.42±7.9)ml,the apical hypertrophic cardiomyopathy group showed a lighter tendency(all P<0.01 compare to the other two groups),two cases in the ApHCM group showed diffuse myocardial fibrosis and 4 cases of severe extensive myocardial fibrosis appeared in the BHCM group.④The overall strain parameters of the left ventricle in the ApHCM group were(GRS:22.27±7.31、GCS:-18.32±2.62、GLS:-9.11±2.83),which was significantly lower than that in the BHCM group(all P<0.01),and GCS and GRS of MVHCM group were-18.35±3.55和24.18±9.11,respectively,which was significantly lower than that of BHCM(both P<0.01),and there was no statistically significant difference between ApHCM and MVHCM.Conclusion When the LVEF retention,patients with ApHCM showed a relatively smaller amount of myocardial fibrosis and lighter diastolic dysfunction.Patients with BHCM showed more severe myocardial fibrosis and diastolic function decreased significantly,but myocardial strain damage was less severe.