Objective To detect left atrial (LA) function and left ventricular (LV)-LA coupling using vector flow mapping (VFM) and two-dimensional tissue tracking (2DTT) echocardiography in patients with diabetes.Methods A total of 51 patients with type 2 diabetes (DM group) and 38 healthy volunteers (control group) were studied.LA and LV strain were assessed by 2DTT.The energy loss (EL) of LA and LV during ventricular systole (ELs),early diastole (ELed),and atrial contraction (ELac) were measured by VFM.Results LVEL in DM group was significantly increased compared to that in control group (P<0.05).LAELs and LAELed in control group were higher than those in DM group (P<0.05);while LAELac decreased in control group (P<0.05).Multivariate regression analysis identified E and LVELed as independent predictors of LAELed;Peak torsion,LA peak systolic strain and LVELac were independent predictors of LAELac.Conclusions The reservoir and conduit function of LA are impaired in patients with DM,while the pump function increases as a compensation.Abnormal LA-LV coupling also appears in patients with DM.

Objective To evaluate the value of left ventricular energy loss (EL) in the systolic left ventricular hemodynamic changes in hypertensive patients by ultrasonic flow vector imaging (VFM). Methods Ninty-eight hypertensive patients were divided into non left ventricular hypertrophy group (NLVH group) and left ventricular hypertrophy group (LVH group) according to the left ventricular mass index(LVMI).Thirty-one healthy adults were erolled as control group.The average total energy loss (EL-T),basal energy loss (EL-B),middle energy loss (EL-M) and apical energy loss (EL-A) of each isovolumic contraction phase,fast ejection phase and slow ejection phase were obtained by VFM,the difference among the three groups were compared.Results ①EL-T and EL-B in isovolumic phase,rapid ejection phase and slow ejection phase in NLVH group were higher than those in control group ( P <0.05 or P <0.01);EL-T,EL-B,EL-M and EL-A in isovolumic phase,rapid ejection phase and slow ejection phase in LVH group were all higher than those in control group ( P <0.05 or P <0.01);EL-M in isovolumic phase and rapid ejection phase,EL-T,EL-B,EL-M and EL-A in slow ejection phase in LVH group were higher than those in the NLVH group ( P <0.05 or P <0.01).② There was a positive correlation between EL-T and LVMI (r=0.311, P < 0.01),EL-B and LVMI ( r = 0.219, P < 0.05),EL-M and LVMI( r = 0.207, P <0.05),EL-T and LVEF( r = 0.340, P < 0.05),EL-B and LVEF( r = 0.367, P < 0.01) in isovolumic contraction phase.There was a positive correlation between EL-B and LVEF( r = 0.359, P < 0.01) in rapid ejection phase.There was a positive relation between EL-B and LVEF( r =0.352,P <0.05) in slow ejection phase.Conclusions The EL of systolic peroid in hypertensive patients increased,which suggests that the left ventricular hemodynamic changes abnormally,VFM can accurately evaluate the changes of hemodynamic during systole.

Objective To simulate the microflow field environment between the anastomotic nail surface and intestinal wall tissue after implantation and to study the effect of hydrophobic surfaces on the flow rate of extracellular fluid and the fluid shear force on the wall to regulate bacterial adhesion through changes in the flow field.Methods The microstructure of shark skin was observed,and a simplified two-dimensional(2D)movement model of bacteria in a microflow field was established.Using computational fluid dynamics(CFD)numerical simulation,the movement of bacteria on a smooth surface and micro-textured surface in a static and dynamic flow field were simulated.The flow field characteristics around bacteria and the magnitude of fluid shear force under the two surface environments were compared,and the internal mechanism of the fluid shear force affecting bacterial adhesion was analyzed.Results The addition of the biomimetic microtexture enhanced the flow rate of the extracellular fluid in the microflow field,and the fluid had little viscous effect on the bacteria in the static flow field.The fluid in the dynamic flow field had a stronger pushing effect on the bacteria.The fluid shear force on the microtextured wall increased when the pit width was within a specific range.Conclusions The bionic micro-textured surface of the anastomotic nail can accelerate the flow rate of extracellular fluid,increase the fluid shear force of micro-textured walls and bacteria,and influence bacterial adhesion.These result provide a theoretical basis for studying bacteriostatic surfaces of anastomotic nails.