Early Diagnosis Of Sarcomere Mutated Gene Carriers In Familial Hypertrophic Cardiomyopathy By Multimodal Imaging

Objective Hypertrophic cardiomyopathy?HCM?gene mutation carriers?genotyped positive/phenotyped negative?at any moment will develope HCM patients,therefore a simple imaging approach for early identification of this part of patients is required.we explore the value of three dimensional speckle tracking imaging?3D-STI?in evaluating the left ventricular systolic function in familiar hypertrophic cardiomyopathy sacomere mutation carriers.Methods Eighty-one subjects were divided as: HCM mutation carriers but without left ventricular hypertrophy?G+/P-??n=41?and normal controls?n=40?.Normal control group including healthy volunteers and healthy family members in whom sarcomere gene mutations were excluded by genetic analysis.They also prospectively underwent 3D-STI to complete strain analysis of the left ventricle.The variables of 3D global systolic longitudinal strain?3D-GLS??3D global systolic radial strain?3D-GRS?and 3D global systolic circumferential strain?3D-GCS?in two groups were compared.Results Compared with normal controls,the G+/P-group showed significantly higher left atrial volume index?P<0.001?.Averaged Ea value by TDI was reduced?P = 0.05?,while averaged E/Ea was higher?P = 0.045?.3D-GLS of G+/P-group showed a notable reduction?P = 0.001?,as well as 3D-GRS?P = 0.009?;however 3D-GCS were not significantly different from controls?P>0.05?.3D-GLS?the cut-off value was?19.5%?determined after ROC analysis identified sacomere mutation carriers with 70.7%sensitivity and 96% specificity,the area under the curve?AUC?was 0.835?95% CI:0.747⁰.924,P<0.001?;3D-GRS?the cut-off value was 43.8%?with 55.0% sensitivity and 65.9% specificity,the AUC was 0.632?95% CI: 0.512⁰.753,P<0.001?.Conclusions The systolic function of left ventricular has changed in familiar hypertrophic cardiomyopathy sacomere mutation carriers,3D-STI could provide quantitative information for gene mutation carriers in early identification.Objective In hypertrophic cardiomyopathy?HCM?,electrocardiographic?ECG?changes have been regarded as the early maker of disease to the HCM mutation carriers but without left ventricular hypertrophy.However,the ECG features of mutation carriers have not been fully characterized.Therefore,we systematically explore the early changes of ECG in sarcomere mutation carriers of familiar hypertrophic cardiomyopathy.Methods Seventy-seven subjects were divided into genotyped positive/phenotyped negative?G+/P-?group?34 HCM sacomere mutation carriers but without left ventricular hypertrophy?and normal control group?43 relatives with no HCM gene mutation carriers?.They also prospectively underwent standard 12-lead ECG and echocardiography,the variables of ECG and echocardiography were compared between two groups.ROC curves were drawn and the efficiency of R wave on the diagnosis of sarcomere mutation carriers was calculated in patients with HCM.Results Compared with normal controls,the P wave and T wave duration,PR?QRS?QT and QTc intervals of G+/P-group showed no significant difference?P>0.05?.The amplitudes of R_V1?R_V2?and R_V1+R_V2+RV3 in G+/P-group were significantly higher than those in control group?P < 0.05?;while there were no significant differences in the amplitudes of RV3?RV4?RV5?RV6 wave between two groups?P>0.05?.The AUC of R_V1 for sarcomere mutation carriers in patients with familiar HCM was 0.721?95% CI:0.602⁰.840,P<0.001?,the optimal cut-off value was 0.425 m V,the sensitivity was 50%and the specificity was 88.4%.The AUC of R_V2 for sarcomere mutation carriers in patients with familiar HCM was 0.714?95% CI: 0.593⁰.835,P<0.001?,the optimal cut-off value was 0.825 m V,the sensitivity was 64.7% and the specificity was 81.4%.Conclusion The early characteristic ECG changes are demonstrated by obviously increased amplitudes of R_V1?R_V2?R_V1+R_V2+RV3 in ECG,which might be earlier than the morphology changes of myocardial hypertrophy.R_V1 and R_V2 could contribute to early indentification of sacomere mutation carriers in HCM.