Assessment of left ventricular regional systolic function by three-dimensional speckle tracking echocardiography in early stage of hypertrophic cardiomyopathy

Objective To assess the left ventricular (LV) regional systolic function by threedimensional speckle tracking imaging (3D-STI) in patients with early stage of hypertrophic cardiomyopathy (HCM).Methods A total of 70 consecutive patients with early stage of HCM were enrolled.In addition,70 healthy subjects were recruited as a control group.A real-time dynamic 3D echocardiography system (IE33) was used to acquire and store LV full-volume 3D images.LV 16 segments longitudinal strain,radial strain,circumferential strain and global strain were analyzed using off-line TomTec software.The difference between the two groups was compared.Results Compared with the control group,LV end diastolic,endsystolic volumes and stroke volume significantly decreased,while LV mass and LV interventricular septum diastolic thickness significantly increased,LV posterior wall diastolic thickness slightly increased (P ＜ 0.001).However,LVEF had no significant difference (P ＞0.05).Compared with the control group,the results were as followed:the longitudinal strain significantly reduced in hypertrophic segments(P ＜0.05),while circumferential and radial strain significantly increased (P ＜ 0.05),global strain showed no significantly difference (P ＞ 0.05).While longitudinal,radial and circumferential strain had no statistical differences in non-hypertrophic segments.A positive linear correlation existed between LV interventricular thickness and LV interventricular longitudinal strain (r =0.287,P =0.006).Conclnsions The impairment of regional myocardial contractility existed in early stage of HCM.The main features were longitudinal strain decreased in hypertrophic segments,which associated with the degree of LV wall thickness,while circumferential and radial strain increased.3D-STI provided a new method for evaluating LV regional systolic function in patients with early stage of HCM. Key words: Echocardiography;  Cardiomyopathy, hypertrophic;  Ventricular function, Left;  Three-dimensional speckle tracking imaging