Objective:To explore the protocol for handgrip exercise stress echocardiography by comparing different maximal voluntary contraction（MVC）handgrip groups with bicycle exercise stress.Methods:Forty-one healthy volunteers were enrolled prospectively from June to October 2024 in Tangdu Hospital and utilized a color Doppler echocardiography system，supine cycle ergometer，and handgrip dynamometer to collect echocardiographic data at baseline，during handgrip exercises at 20%（3 min），30%（3 min），and 40%（2 min）of MVC，and spine bicycle exercise stress at peak. Parameters measured included left ventricular ejection fraction（EF），stroke volume（SV），cardiac output（CO），mitral inflow E-wave and A-wave velocities，lateral and septal mitral annular e' velocities，E/A and E/e' ratios，global longitudinal strain（GLS），left atrial reservoir strain（LAS R），conduit strain（LAS CD），and contractile strain（LAS CT）. The non-invasive myocardial work indices were also assessed，including global work index（GWI），global constructive work（GCW），global wasted work（GWW），and global work efficiency（GWE）. Statistical analyses were performed using repeated measures analysis of variance，with corrected paired t-test for comparisons between two exercise stress states. Results:Compared with the baseline state，heart rate，blood pressure，CO、GWI、GCW、GWW and LAS CT gradually increased，while EF、E/A、GLS、GWE、LAS R and LAS CD gradually decreased under 20%，30% and 40% of MVC states. The changes were most obvious at 40% of MVC state，which was selected for the handgrip exercise stress echocardiography protocol.Compared with the peak of bicycle exercise，at 40% of MVC，heart rate was significantly lower［（81.2 ± 9.7）bpm vs.（164.6 ± 11.3）bpm， P<0.05）］，systolic blood pressure was slightly lower［（152.9 ± 13.2）mmHg vs.（165.1 ± 20.4）mmHg， P<0.05］，diastolic blood pressure was higher［（96.0 ± 9.5）mmHg vs.（89.5 ± 10.9）mmHg， P<0.05］，GLS was lower［（19.1 ± 1.5）% vs.（23.5 ± 1.7）%， P<0.05］，GWI was similar［（2 254.2 ± 417.3）mmHg% vs.（2 227.5 ± 389.0）mmHg%， P>0.05］，but GWE was higher［（95.3 ± 2.0）% vs.（93.7 ± 2.0）%， P<0.05］，and LAS R was lower［（39.4 ± 4.2）% vs.（43.9 ± 4.1）%， P<0.05］. Conclusions:The 40% of MVC lasting 2 min can cause the most significant handgrip-related changes in cardiac function and can be used as the standard protocol for handgrip exercise stress echocardiography. Handgrip stress exercise can cause significant changes in cardiac systole，diastole，and work performance，showing different characteristics compared with bicycle exercise stress.

Objective:To assess the clinical utility of vector flow mapping（VFM）for evaluating left ventricular wall shear stress（WSS）in individuals with non-obstructive hypertrophic cardiomyopathy（nHCM）.Methods:Forty patients with non-obstructive HCM（nHCM）and 46 healthy volunteers in Tangdu Hospital of Air Force Medical University from May 2020 to September 2023 were enrolled prospectively in this study. The left ventricular WSS of each of 18 segments was measured and analyzed by VFM during rapid filling phase（T1），slow filling phase（T2），isovolumetric contraction phase（T3）and rapid ejection phase（T4）.Results:① WSS decreased gradually from basal to apical segments in control group，while there was no such change pattern in nHCM group. ② Diastolic phase：When compared to the control group，the nHCM group demonstrated significantly increased WSS across all segments of the inferoseptal regions，the basal anteroseptal segment，and the middle and apical inferior segments during the T1 stage. Additionally，at the T2 stage，the WSS was significantly higher in the nHCM group across all segments of the inferoseptal and anteroseptal regions，the basal anterolateral segment，and the apical inferolateral and anterior segments（all P<0.05）. Conversely，during the T1 stage，the basal anterolateral segment，basal inferolateral segment，and the middle and apical anteroseptal segments，as well as during the T2 stage，the basal and middle inferior segments，exhibited lower WSS values compared to the control group，with these differences being statistically significant（all P<0.05）. ③Systolic Phase：During the T3 stage，the WSS values in all segments of the anteroseptal and anterolateral regions，as well as the apical inferior and anterior segments，were significantly elevated in the nHCM group compared to the control group（all P<0.05）.At the T4 stage，WSS in each segment of the inferolateral and inferior regions，as well as the basal and middle anterior segments，was significantly elevated in the nHCM group compared to the control group（all P<0.01）. Conversely，during the same stage，the WSS values in the basal inferolateral segment，the basal and middle anterolateral segments，and the basal and middle anteroseptal segments were significantly lower in the nHCM group than in the control group，with all differences reaching statistical significance（all P<0.01）.Regarding global WSS，the left ventricular global WSS in the nHCM group was significantly higher than that in the control group at both the T2 and T3 stages（all P<0.001）. Furthermore，the global WSS at the T3 stage was negatively correlated with left ventricular end-systolic volume，end-diastolic volume，and left ventricular stroke volume（ r=-0.226， P=0.036； r=-0.345， P=0.001； r=-0.303， P=0.005）. Conclusions:Significant differences in WSS are observed between patients with nHCM and control groups at various phases. WSS may serve as an early indicator of changes in cardiac function in nHCM patients.

Objective:To explore the protocol for handgrip exercise stress echocardiography by comparing different maximal voluntary contraction（MVC）handgrip groups with bicycle exercise stress.Methods:Forty-one healthy volunteers were enrolled prospectively from June to October 2024 in Tangdu Hospital and utilized a color Doppler echocardiography system，supine cycle ergometer，and handgrip dynamometer to collect echocardiographic data at baseline，during handgrip exercises at 20%（3 min），30%（3 min），and 40%（2 min）of MVC，and spine bicycle exercise stress at peak. Parameters measured included left ventricular ejection fraction（EF），stroke volume（SV），cardiac output（CO），mitral inflow E-wave and A-wave velocities，lateral and septal mitral annular e' velocities，E/A and E/e' ratios，global longitudinal strain（GLS），left atrial reservoir strain（LAS R），conduit strain（LAS CD），and contractile strain（LAS CT）. The non-invasive myocardial work indices were also assessed，including global work index（GWI），global constructive work（GCW），global wasted work（GWW），and global work efficiency（GWE）. Statistical analyses were performed using repeated measures analysis of variance，with corrected paired t-test for comparisons between two exercise stress states. Results:Compared with the baseline state，heart rate，blood pressure，CO、GWI、GCW、GWW and LAS CT gradually increased，while EF、E/A、GLS、GWE、LAS R and LAS CD gradually decreased under 20%，30% and 40% of MVC states. The changes were most obvious at 40% of MVC state，which was selected for the handgrip exercise stress echocardiography protocol.Compared with the peak of bicycle exercise，at 40% of MVC，heart rate was significantly lower［（81.2 ± 9.7）bpm vs.（164.6 ± 11.3）bpm， P<0.05）］，systolic blood pressure was slightly lower［（152.9 ± 13.2）mmHg vs.（165.1 ± 20.4）mmHg， P<0.05］，diastolic blood pressure was higher［（96.0 ± 9.5）mmHg vs.（89.5 ± 10.9）mmHg， P<0.05］，GLS was lower［（19.1 ± 1.5）% vs.（23.5 ± 1.7）%， P<0.05］，GWI was similar［（2 254.2 ± 417.3）mmHg% vs.（2 227.5 ± 389.0）mmHg%， P>0.05］，but GWE was higher［（95.3 ± 2.0）% vs.（93.7 ± 2.0）%， P<0.05］，and LAS R was lower［（39.4 ± 4.2）% vs.（43.9 ± 4.1）%， P<0.05］. Conclusions:The 40% of MVC lasting 2 min can cause the most significant handgrip-related changes in cardiac function and can be used as the standard protocol for handgrip exercise stress echocardiography. Handgrip stress exercise can cause significant changes in cardiac systole，diastole，and work performance，showing different characteristics compared with bicycle exercise stress.

Objective:To assess the clinical utility of vector flow mapping（VFM）for evaluating left ventricular wall shear stress（WSS）in individuals with non-obstructive hypertrophic cardiomyopathy（nHCM）.Methods:Forty patients with non-obstructive HCM（nHCM）and 46 healthy volunteers in Tangdu Hospital of Air Force Medical University from May 2020 to September 2023 were enrolled prospectively in this study. The left ventricular WSS of each of 18 segments was measured and analyzed by VFM during rapid filling phase（T1），slow filling phase（T2），isovolumetric contraction phase（T3）and rapid ejection phase（T4）.Results:① WSS decreased gradually from basal to apical segments in control group，while there was no such change pattern in nHCM group. ② Diastolic phase：When compared to the control group，the nHCM group demonstrated significantly increased WSS across all segments of the inferoseptal regions，the basal anteroseptal segment，and the middle and apical inferior segments during the T1 stage. Additionally，at the T2 stage，the WSS was significantly higher in the nHCM group across all segments of the inferoseptal and anteroseptal regions，the basal anterolateral segment，and the apical inferolateral and anterior segments（all P<0.05）. Conversely，during the T1 stage，the basal anterolateral segment，basal inferolateral segment，and the middle and apical anteroseptal segments，as well as during the T2 stage，the basal and middle inferior segments，exhibited lower WSS values compared to the control group，with these differences being statistically significant（all P<0.05）. ③Systolic Phase：During the T3 stage，the WSS values in all segments of the anteroseptal and anterolateral regions，as well as the apical inferior and anterior segments，were significantly elevated in the nHCM group compared to the control group（all P<0.05）.At the T4 stage，WSS in each segment of the inferolateral and inferior regions，as well as the basal and middle anterior segments，was significantly elevated in the nHCM group compared to the control group（all P<0.01）. Conversely，during the same stage，the WSS values in the basal inferolateral segment，the basal and middle anterolateral segments，and the basal and middle anteroseptal segments were significantly lower in the nHCM group than in the control group，with all differences reaching statistical significance（all P<0.01）.Regarding global WSS，the left ventricular global WSS in the nHCM group was significantly higher than that in the control group at both the T2 and T3 stages（all P<0.001）. Furthermore，the global WSS at the T3 stage was negatively correlated with left ventricular end-systolic volume，end-diastolic volume，and left ventricular stroke volume（ r=-0.226， P=0.036； r=-0.345， P=0.001； r=-0.303， P=0.005）. Conclusions:Significant differences in WSS are observed between patients with nHCM and control groups at various phases. WSS may serve as an early indicator of changes in cardiac function in nHCM patients.

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Objective:To reveal the diurnal variation characteristics of the exercise adaptability of cardiac function in healthy men of different ages by the analysis of echocardiographic parameter changes before and after exercise intervention using the left ventricular pressure-strain loop techniques.Methods:A prospective control design was used to collect 193 healthy male volunteers from October 2022 to July 2023 in Tangdu Hospital, 101 in the young group [(26±5) years old], and 92 in the middle-aged group [(50±4) years old]. The heart rate, blood pressure and routine echocardiographic parameters were collected at rest and after exercise stress (3-minute step test) at 7∶00 a.m.and 10∶00 p.m., respectively. The heart rate, blood pressure cardiac output, and echocardiographic parameters [anteroposterior diameter of left atrium (LAD), ratio of peak early diastolic flow velocity to late diastolic peak flow velocity of mitral valve (E/A), left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVEDS)] were then determined. The parameters of myocardial work including left ventricular longitudinal strain (GLS), global work index (GWI), global work efficiency (GWE), global constructive work (GCW) and global wasted work (GWW) were obtained by left ventricular pressure-strain loop technique. The differences of the parameters above between before and after step test, morning and night, young group and middle-aged group were compared.Results:The heart rate, blood pressure and cardiac output of young and middle-aged healthy men increased significantly in the morning and night step test (all P<0.05), GLS, GWI, GCW and GWW were significantly higher than those in resting state (all P<0.05), and GWE was significantly lower than that in resting state ( P<0.05). The change rates of heart rate, cardiac output, GLS, GWI and GCW in the early morning were significantly higher than those at night (all P<0.05), while the change rates of blood pressure and GWE in each group were significantly lower than those at night ( P<0.05). The change rates of heart rate, systolic blood pressure, GLS and GWI in the middle-aged group were significantly higher than those in the young group in the morning and night (all P<0.05), while the change rate of diastolic blood pressure at night was significantly higher than that in the young group ( P<0.05), but there was no significant difference in the morning ( P>0.05). Conclusions:The cardiac adaptability of healthy men has obvious circadian rhythm, characterized by being of low in the morning and high in the evening. Age mainly affects the cardiac adaptability in the morning. The response to low-intensity load stimulation increases with aging, indicating the decrease of morning cardiac adaptability.

Objective:To investigate the clinical applicability of the four-grade grading(G4) advocated by the academy in recent years compared with the guideline-recommended three-grade grading(G3) in functional tricuspid regurgitation (FTR).Methods:A total of 137 consecutive patients were prospectively included from outpatient and inpatient clinics at Tangdu Hospital, Air Force Medical University from May to December 2023. All patients underwent echocardiography and were graded for regurgitation based on the 2017 American Society of Echocardiography Valve Evaluation Guidelines as the reference standard. The patients with regurgitation were grouped according to the G3 based on the guidelines and the G4 advocated by the academic community in recent years, respectively. The consistency of the regurgitation grading between multi-indicators and single-indicators was analyzed using the Kappa test for both G3 and G4. The quantitative regurgitation relevant parameters were analyzed using ROC curves to evaluate the diagnostic efficacies for G4, including the vena contracta width (VCW), the area of the color flow jet (A Jet), and the radius of the PISA (R PISA). Results:The results of consistency analysis showed that the consistency of regurgitation volume (RVol) was significantly higher in the G4 multi-indicators comprehensive assessment versus the single-indicators assessment compared with the G3, with a Kappa value of 0.84 vs. 0.30. The consistency of effective regurgitant orifice area (EROA) and VCW remained unchanged, with a Kappa value of 0.76 vs. 0.89, 0.51 vs. 0.66. ROC curve analysis showed that for the G4, the area under the curve (AUC) for moderate regurgitation were 0.854, 0.993, and 0.894, respectively, while for moderate-severe regurgitation, these values were 0.899, 0.979, and 0.917, respectively.Conclusions:For FTR, the G4 currently advocated by the academic community has better consistency between single-indicators and comprehensive indicators grading than the G3 based on the guideline, which is clinically applicable; A Jet, R PISA, and VCW can be supplemented to the G4, which helps to improve the quantitative assessment system.

Objective:To evaluate the performance of the self-developed transcranial ultrasound patch probe as well as its stability and safety in clinical applications.Methods:This study was a cross-sectional study. Fifty healthy subjects in Tangdu Hospital from October to December 2023 were randomly and equally divided into two groups using a simple randomization method. The transcranial Doppler ultrasound (TCD) examinations were performed using the self-developed transcranial ultrasound patch probe and normal TCD probe alternatively in each group from squatting to sitting and then to standing posture. Two experienced sonographers (A, B) each completed one test for the same subject using the above two different probes. The differences of the ultrasound parameters of middle cerebral artery (MCA) blood flow measured by the self-developed transcranial ultrasound patch probe and the normal TCD probe in different postures (squatting, sitting, standing) were compared. At the same time, operator satisfaction with the use of the two probes was assessed in terms of time taken to obtain satisfactory images, operational comfort, and ease of handling. In addition, the subject's comfort during the examination was examined, and the signal acquisition stability of the two probes was comprehensively evaluated.Results:There was no significant difference in detection of various ultrasound parameters of MCA between using the transcranial patch probe and the normal TCD probe (all P>0.05). The overall satisfaction of transcranial ultrasound patch probe and normal TCD probe was quite similar. The transcranial ultrasound patch probe acquired favorable and stable signals. No subjects experienced adverse events/accidents during the examination of the subjects using the transcranial ultrasound patch probe as well as the normal TCD probe.Both probes had good and stable signal acquisition. Conclusions:TCD examinations could be well performed using the transcranial ultrasound patch probe, which might provide a potential new method for real-time monitoring and evaluating of cerebral blood flow of a moving subject.

Ultrasound medicine plays a great role in innovative diagnosis and treatment especially when the interdisciplinary characteristics are considered.Cultivating versatile postgraduate students with interdisciplinary capacity is an essential requirement for talent development and disciplinary advancement in ultrasonography.However, limited by factors such as the knowledge structure of the students, the subject background of the supervisors and tutors, policies and regulations, etc., and it is difficult for a single-disciplinary training team to meet the multi-disciplinary requirements of the ultrasound medical profession.In the process of cultivating postgraduate students in cooperation with molecular biology supervisors and tutors, our team has initially explored a set of training paths for inter-disciplinary ultrasound medical postgraduate students.This article systematically sorted out the practical experience of the above-mentioned training model from aspects such as student selection, supervisor and tutor team building, curriculum setting, literature reading ability cultivation, process management, scientific research results sharing mechanism, etc., hoping to provide reference for inter-disciplinary team cooperation in cultivating inter-disciplinary talents.

Background: Gut microbiota is closely related to the occurrence and development of diabetes and affects the prognosis of diabetic complications, and the underlying mechanisms are only partially understood. We aimed to explore the possible link between the gut microbiota and vascular inflammation of diabetic mice. Methods: The db/db diabetic and wild-type (WT) mice were used in this study. We profiled gut microbiota and examined the and vascular function in both db/db group and WT group. Gut microbiota was analyzed by 16s rRNA sequencing. Vascular function was examined by ultrasonographic hemodynamics and histological staining. Clostridium butyricum (CB) was orally administered to diabetic mice by intragastric gavage every 2 days for 2 consecutive months. Reactive oxygen species (ROS) and expression of nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were detected by fluorescence microscopy. The mRNA expression of inflammatory cytokines was tested by quantitative polymerase chain reaction. Results: Compared with WT mice, CB abundance was significantly decreased in the gut of db/db mice, together with compromised vascular function and activated inflammation in the arterial tissue. Meanwhile, ROS in the vascular tissue of db/db mice was also significantly increased. Oral administration of CB restored the protective microbiota, and protected the vascular function in the db/db mice via activating the Nrf2/HO-1 pathway. Conclusion This study identified the potential link between decreased CB abundance in gut microbiota and vascular inflammation in diabetes. Therapeutic delivery of CB by gut transplantation alleviates the vascular lesions of diabetes mellitus by activating the Nrf2/HO-1 pathway.