ABSTRACT
Purpose This study aims to observe the hemodynamic state of the carotid artery in healthy volunteers and diabetes patients via ultrasound vector flow imaging(V-Flow),and to quantitatively analyze the characterization of wall shear stress(WSS)in different degrees of atherosclerosis carotid artery.Materials and Methods This was a cross-sectional study.Forty four diabetic patients diagnosed in Sichuan Provincial People's Hospital from April 2019 to June 2019 were retrospectively analyzed.Routine carotid ultrasound examination and V-Flow imaging were performed on 44 diabetic patients(88 vessels)and 15 controls(30 vessels).According to the results of carotid ultrasound examination,diabetic patients were divided into normal intima-media thickness(IMT)group,IMT thickening group and plaque group.The differences of WSS in different parts of carotid artery between diabetic patients and controls were observed,and the changes of WSS in different groups of diabetic patients were further compared and analyzed.Results In this study,the WSS(including WSSmax and WSSmean)of the bifurcation and middle segment of the common carotid artery in diabetic patients were significantly lower than those in the normal control group(P=0.001,P=0.003).WSS at the bifurcation of common carotid artery was significantly smaller than that at the middle segment of common carotid artery in both normal control group and diabetic group(P=0.001).WSS at the bifurcation of common carotid artery in diabetic patients was changed with the severity of atherosclerosis(P=0.018 and P=0.043),and was highest in the plaque group[WSSmax(2.58±0.69)Pa;WSSmean(0.86±0.25)Pa],followed by IMT thickening group[(2.37±0.69)Pa;(0.77±0.35)Pa].The WSS was lowest in the normal IMT group[(2.13±0.52)Pa;(0.69±0.20)Pa].There was no significant difference in WSS of the middle segment of common carotid artery among the three groups(P>0.05).Conclusion The WSS in the bifurcation and middle section of common carotid artery in diabetic patients is lower than that in controls,and it changed with the increase of atherosclerosis degree.Therefore,the V-Flow technique of ultrasonic vector flow imaging has a certain value in evaluating the progression of carotid atherosclerosis in diabetic patients.
ABSTRACT
Echocardiogram is vital for the diagnosis of cardiac disease. The heart has complex hemodynamics requiring an advanced ultrasound imaging mode. Cardiac ultrasound vector flow imaging is capable of measuring the actual magnitude and direction of the blood flow velocity, obtaining the quantitative parameters of hemodynamics, and then providing more information for clinical research and diagnosis. This study mainly reviewed several different vector flow imaging techniques for cardiac flow and presented the implementation difficulties, and proposed a diverging wave based high frame rate cardiac ultrasound vector flow imaging. The study discussed the limitation of current ultrasound technology used in the cardiac flow measurement, analyzed and demonstrated the specific reasons for these implementation difficulties and the potential future development.
Subject(s)
Blood Flow Velocity , Heart/physiology , Hemodynamics , UltrasonographyABSTRACT
Objective@#To evaluate the changes of intraventricular pressure differences (IVPDs) and intraventricular pressure gradients (IVPGs) in different phases of cardiac cycle in patients with heart failure(HF) patients by relative pressure imaging based on vector flow imaging(VFM).@*Methods@#Forty-nine HF patients with left ventricular ejection fraction (LVEF) lower than 0.50 hospitalized in Qilu Hospital of Shandong University from November 2018 to January 2019, including thirty-three patients with HF with reduced ejection fraction (HFrEF group) and fifteen patients with midrange ejection fraction (HFmrEF group), and forty-three controls were enrolled in this study. Clinical data and echocardiographic images were collected and the conventional left ventricular diameter, mass, volume, and systolic and diastolic function parameters were measured. IVPDs and IVPGs during isovolemic systole (IC), rapid ejection (RE), isovolemic diastole (IR), rapid filling (RF) and atrial systole (AC) phases were obtained by the VFM technique. The changes of IVPDs and IVPGs in different phases between the HF and control groups, and their correlations with conventional ultrasound parameters were analyzed.@*Results@#IVPDs and IVPGs in heart failure group were significantly reduced compared with the control group especially in isovolumic relaxation phase(all P<0.001). IVPDs and IVPGs showed a decreasing trend in the control group, HFmrEF group and the HFrEF group(P<0.001). IVPDs and IVPGs were correlated with LVID, LVMI, ESV, LVEF, GLS and E/e′ (all P<0.01), among which IVPD-IR and IVPG-IR were best correlated. IVPD-IR and IVPG-IR had excellent diagnostic efficacy for HF patients with LVEF<0.5, with cut-off values of <0.73 mmHg (AUC=0.915, P<0.001) and <0.103 mmHg/cm (AUC=0.932, P<0.001), respectively.@*Conclusions@#Early diastolic hemodynamics are severely impaired when systolic function declines.IVPG-IR, as a marker of left ventricular diastolic function, significantly correlates with left ventricular systolic function, and can be used as a potential indicator for assessing left ventricular systolic and diastolic function in patients with heart failure and identifying patients with heart failure.
ABSTRACT
Objective To evaluate the changes of intraventricular pressure differences(IVPDs)and intraventricular pressure gradients(IVPGs)in different phases of cardiac cycle in patients with heart failure (HF)patients by relative pressure imaging based on vector flow imaging(VFM).Methods Forty-nine HF patients with left ventricular ejection fraction (LVEF) lower than 0.50 hospitalized in Qilu Hospital of Shandong University from November 2018 to January 2019,including thirty-three patients with HF with reduced ejection fraction (HFrEF group) and fifteen patients with midrange ejection fraction (HFmrEF group),and forty-three controls were enrolled in this study.Clinical data and echocardiographic images were collected and the conventional left ventricular diameter,mass,volume,and systolic and diastolic function parameters were measured. IVPDs and IVPGs during isovolemic systole (IC),rapid ej ection (RE), isovolemic diastole (IR),rapid filling (RF) and atrial systole (AC) phases were obtained by the VFM technique.The changes of IVPDs and IVPGs in different phases between the HF and control groups,and their correlations with conventional ultrasound parameters were analyzed.Results IVPDs and IVPGs in heart failure group were significantly reduced compared with the control group especially in isovolumic relaxation phase(all P <0.001).IVPDs and IVPGs showed a decreasing trend in the control group, HFmrEF group and the HFrEF group(P<0.001).IVPDs and IVPGs were correlated with LVID,LVMI,ESV,LVEF,GLS and E/e'(all P <0.01),among which IVPD-IR and IVPG-IR were best correlated. IVPD-IR and IVPG-IR had excellent diagnostic efficacy for HF patients with LVEF<0.5,with cut-off values of<0.73 mmHg(AUC=0.915,P<0.001)and <0.103 mmHg/cm(AUC=0.932,P<0.001), respectively.Conclusions Early diastolic hemodynamics are severely impaired when systolic function declines.IVPG-IR,as a marker of left ventricular diastolic function,significantly correlates with left ventricular systolic function,and can be used as a potential indicator for assessing left ventricular systolic and diastolic function in patients with heart failure and identifying patients with heart failure.