Evaluation On Early-stage Left Ventricular Systolic Strain And Synchronism In Pathogenic Gene Carriers Of Familial Hypertrophic Cardiomyopathy By Three-dimensional Speckle Tracking Imaging

Objective Three-dimensional speckle tracking imaging(3D-STI)was used to evaluate the early changes of the global and regional systolic strain and its synchronism in the left ventricle of carriers of pathogenic genes of familial hypertrophic cardiomyopathy(FHCM),which provided an objective basis for the early diagnosis,follow-up,therapeutic effect and prognosis evaluation of such patients.Methods Six HCM families were included in this study.A new generation of high-throughput sequencing technology(NGS)was used to detect the genes of HCM probands in the family and analyze the genetics.The pathogenic mutation sites were locked.The members of the family used Sanger method to sequence the specific known pathogenic mutations.22 patients were screened in the HCM pathogenic gene carriers group(G-Pgroup)and 30 in the control group(G-P-group).A total of 17 HCM patients who met the inclusion criteria of this study were enrolled into the G+P+ group.Using the Philips iE33 Doppler ultrasound diagnostic system to collect the required two-dimensional data and measure the relevant index values,replace the X5-1 type probe,collect the three-dimensional full volume image,import the TomTec three-dimensional ultrasound image processing software,the software automatically measured the global and 16 segment systolic strain index values in all directions of the left ventricle,and calculated the relevant indexe values toevaluate the left ventricle dyssynchrony.The above-mentioned indicators are compared between the three groups to determine whether there are differences.Results 1.The results of gene detection showed that there were 19 cases with MYBPC3 gene mutation(G+P+ 6,G+P-13),13 cases with TTN gene mutation(G+P+ 9,G+P-4),10 cases with TNNI2 gene mutation(G+P+ 2,G+P-8),3 cases with MYH7 gene mutation(G+P+2,G+P-1),among them,6 cases(G+P+ 2,G+P-4)had both MYBPC3 and TNNI2 gene mutations.2.Compared with G-P-group,Ea and Ea/Aa decreased and E/Ea increased in G+P-group(P<0.05),but there was no significant difference in other indexes(P>0.05);compared with G+P+ group,IVSD,LVPWD,LAVI,LVMI and E/Ea G+P-group had no significant increase in G+P+ group,LVEDV,LVESV,SV and Ea G+P-group had no significant decrease in G+P+ group,IVRT was significantly longer in G+P+ group(P<0.05).3.Compared with G-P-group,GLS in G+P-group decreased significantly(P<0.05);compared with G+P+ group,GLS and GRS in G+P-group did not decrease significantly(P<0.05),GCS had no statistical difference(P>0.05),but G+P+ group had an increasing trend.4.Compared with the G-P-group,the longitudinal strain of the anterior apical segment,the anterior septal basal segment and the posterior septal basal segment in the G+P-group was significantly reduced(P<0.05);compared with the G+P+ group,the longitudinal strain of the anterior apical segment,posterior septal middle segment,inferior septal basal segment and posterior septal basal segment in the G+P-group was not significantly reduced(P<0.05).5.Compared with G-P-group,there was no significant difference in the circumferential strain index of each segment(P>0.05);compared with G+P+group,there was no significant increase in the circumferential strain of apical and basal segments of interventricular septum in G+P-group(P<0.05).6.Compared with G-P-group,there was no significant difference in radial strain index of each segment(P>0.05);compared with G+P+group,there was no significant decrease in radial strain of middle post septum,basal segment of anterior septum and basalsegment of inferior wall in G+P-group(P<0.05).7.Compared with G-P-group,TLS diff% of G+P-group was significantly prolonged(P<0.05),and there was no significant difference in other parameters(P>0.05);Compared with G+P+ group,TLS-SD%,TRS-SD%,TRS-diff%,TAS-SD%,TAS-diff% G+P-group had no significant prolongation(P<0.05).Conclusion 1.This study showed that LS decreased in global and part of segments of carriers of HCM pathogenic genes,suggesting that LS is the earliest strain indicator for abnormal appearance,and has important reference value for early detection of left ventricular systolic dysfunction,monitoring of disease progression and evaluation of prognosis.2.This study showed that there was no significant difference between the whole and each segment CS index of HCM pathogenic gene carriers and the G-P-group,suggesting that although the carriers of the pathogenic gene showed a decrease in LS,but CS remained relatively stable,it is a compensation mechanism for the damage.3.The TLS-diff% of HCM pathogenic gene carriers was significantly prolonged,suggesting that the ventricular longitudinal contraction dyssynchrony had occurred when the ventricular wall had not developed hypertrophy.The maximum thickness of left ventricular wall should be combined with 3D-STI dyssynchrony index for HCM patients and their families as the objective basis to guide the formulation of clinical treatment plan and evaluation of curative effect.