Objective To explore the influence of gender and age on hip and plantar pressure changes in the sit-to-stand transition. Methods Kinematic parameters such as changes in hip joint angle,motor velocity and speed,and also plantar pressure changes such as stress,pressure and contact area were observed as subjects of different ages and genders performed sit-to-stand transitions. Results ①Hip kinematics:The speeds of trunk movement and hip joint angle change in men and women were significantly different.Their average speed in rising was also significantly different.The young and middle-aged people rose faster with faster hip joint angle changes than the elderly.Their total rising time was therefore significantly shorter as well.()Plantar pressure kinematics:The men's plantar pressures were significantly higher than those of the women throughout the rising process.The plantar pressure of the young and middle-aged subjects was also significantly higher than that of the elderly.At the last stage of sit-to-stand transfer process the ground contact area of the women's was significantly larger,on average,than that of the men,and the elderly had significantly larger contact areas than young or middle-aged people. Conclusion During sit-to-stand transfers,men and young people move faster than women or the elderly.Women and older people tend to have larger foot-ground contact areas than men and younger persons.Different rehabilitation measures are required for different ages,genders and diseases.

Objective: To observe the hemodynamic change characteristics of left ventricle and evaluate left ventricular systolic function in patients with chronic heart failure (CHF) via vector flow mapping(VFM). Methods: Sixty-two patients with CHF(CHF group) were selected as case group and were divided into three groups (B, C, D) according to the American College of Cardiology Foundation and the American Heart Association (ACC/AHA ) recommended stages.Sixty healthy volunteers were selected as control group. The left ventricular circulation parameters (vortex quantity, vortex area, circulation) and energy loss (EL) of the apex, mid, and basal segments in different groups were compared in all the systolic phases. Left ventricular ejection fraction (LVEF) was calculated by biplane Simpson method, and the correlation was analyzed with the parameters of circulation and EL. Results: ①In the phase of isovolumetric contraction (IVC) and slow ejection (SE), compared with the control group, the levels of EL were increased in mid and basal segments (P<0.01 or P<0.05) in CHF group. The vortex area and circulation during IVC and rapid ejection (RE) were higher in CHF group than those in the control group (P<0.01 or P<0.05). As for SE, only vortex quantity was higher in CHF group than that in the control group (P<0.05). ②In CHF group, EL were increased at stage B and stage C than those in the control group (P<0.05), and EL were decreased at stage D than those in the control group ( P<0.05). Meanwhile, there was decreased tendency of EL in CHF group with the increase of ACC/AHA stages. ③The circulation during IVC of phase D was higher in CHF group than that in the control group (P<0.05), the vortex area during RE was greater in CHF group than that of the control group and stage B (P<0.05). ④EL was positively correlated with LVEF at basal segment of IVC(r=0.615, P<0.001). The vortex area during RE, circulation during IVC and RE were negtively correlated with LVEF (r=-0.598, -0.594, -0.623; all P<0.001). Conclusions VFM technology can quantify the left ventricular hemodynamic changes of patients with CHF in the systolic phase, and shows its relationship with left ventricular systolic function, to provide objective basis for grading of CHF and also provide objective quantitative indicators for clinical treatment and curative effect evaluation.

Objective: To explore the value of parameters obtained by dual-pulse wave Doppler to predict the recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation(RFCA) and the value of the technology to evaluate the left ventricular diastolic function of the AF. Methods: Sixty-seven AF patients who were subjected to ablation were selected as the case group, and 47 patients with sinus rhythm were matched as control group. The general clinical data of the case group and the control group was collected, routine ultrasound examination and dual-pulse wave Doppler examination were performed to all of them. A 24-hour Holter examination was performed at 3, 6 and 12 months after radiofrequency catheter ablation in the case group, the patients were divided into two groups with and without recurrence according to the results. Dual-pulse wave Doppler parameters included: ①the time interval between the onset of early transmitral flow velocity (E) and that of early diastolic mitral annular velocity (e′) (TE-e′); ②peak early diastolic transmitral flow velocity (E) and tissue Doppler septal (S) mitral annular early diastolic velocity (e′), peak early diastolic transmitral flow velocity (E) and tissue Doppler lateral (L) mitral annular early diastolic velocity (e′), E/e′(S) and E/e′(L). The differences between the case group and the control group, and between the recurrent and the non-recurrent group were compared. The factors influencing the recurrence of AF after RFCA were analyzed with univariate and multivariate Logistic regression. Results: ①The parameters E/e′(S), E/e′(L) and TE-e′ of case group were higher than those of control group (all P<0.05); ②During follow-up examinations after the ablation, 21 (31.34%) patients recurred. TE-e′ of the recurrence group was higher than that in the nonrecurrence group (P<0.001). The parameters E/e′(S) and E/e′(L) in the recurrence group had no difference compared with those in nonrecurrence group without recurrence(all P>0.05); ③Univariate and multivariate Logistic regression suggested that TE-e′ was an independent predictor for the recurrence of AF patients after the ablation(P=0.001). Conclusions Dual-pulse wave Doppler can evaluate left ventricular diastolic function of atrial fibrillation, TE-e′ is an independent predictor for the recurrence of AF patients after radiofrequency catheter ablation.

Objective:To evaluate the characteristics of diastolic left intraventricular pressure differences(IVPD) and intraventricular pressure gradients(IVPG) among normal adults in different ages by vector flow mapping.Methods:From March 2019 to October 2020, 1 093 healthy volunteers were selected from the physical examination center of the Second Affiliated Hospital of Harbin Medical University, and they were divided into youth group (18-40 years old), middle-aged group (41-65 years old) and elderly group (>65 years old). IVPD and IVPG during isovolumetric relaxation(IR) period, rapid filling (RF) period, slow filling(SF) period, and atrial contraction(AC) period were measured by vector flow mapping, and were correlated with left ventricular diastolic function parameters.Results:①IVPD-IR, IVPD-AC, IVPG-IR, and IVPG-AC gradually increased while IVPD-RF, IVPD-SF, and IVPG-RF gradually decreased from the youth group to the elderly group(all P<0.05). ②IVPD-RF and IVPG-RF were positively correlated with E( r=0.391, 0.402, P<0.001, respectively). IVPD-AC and IVPG-AC were positively correlated with A( r=0.407, 0.425, P<0.001, respectively) and E/e′( r=0.268, 0.294, P<0.001, respectively) while negatively correlated with E/A( r=-0.510, -0.506, P<0.001, respectively) and e′/a′( r=-0.514, -0.511, P<0.001, respectively). Conclusions:IVPD and IVPG can quantitatively analyze the changes of left ventricular hemodynamics in normal subjects, which are expected to be new indexes to evaluate left ventricular diastolic function.

Objective:To observe the change of the left ventricular(LV) wall shear stress (WSS) using vector flow mapping (VFM) in different segments at each phase of diastolic period among normal subjects.Methods:From August 2018 to March 2019, 200 healthy volunteers selected from the Physical Examination Center of the Second Affiliated Hospital of Harbin Medical University were recruited. The WSS values of LV segments at the same and at different phases[isovolumic relaxation period(D1), rapid filling period(D2), slow filling period(D3), atrial contraction period(D4)] in diastole were measured and analyzed.Results:①The relationships of the WSS of LV different segments at the same phase of diastolic period: The WSS values of anterior septum, posterior septum and posterior wall during D1, and the WSS values of posterior septum, posterior wall and inferior wall during D2 showed basal>middle>apical segments, the differences were statistically significant (all P<0.05). ②The changes of the WSS values of LV different segments during diastolic period: During D1-D2-D3-D4 period, the absolute values of WSS in anterior septum, posterior septum, anterior wall, lateral wall and inferior wall showed an increasing-decreasing-increasing trend. During D2-D3-D4 period, the absolute values of WSS in the posterior wall showed a decreasing-increasing trend. During D1-D2-D3-D4 period, the absolute values of WSS in the apical segment of anterior septum, basal and middle segments of posterior septum, basal, middle and apical segments of anterior wall, basal segment of lateral wall, the middle and apical segments of posterior wall, basal and middle segments of inferior wall all showed an increasing-decreasing-increasing trend, the difference was statistically significant (all P<0.05). Conclusions:The LV WSS in different segments at the same phase or in the same segment at the different phases in diastole exhibit a regular change and is consistent with the LV hemodynamic changes, which indicates that WSS can quantitatively reflect the hemodynamic changes of the LV in normal subjects.