Research Progress on Vector Flow Imaging of Cardiac Ultrasound / 中国医疗器械杂志

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.

Application of vector flow mapping technique in the assessment of left intraventricular pressure gradients in heart failure patients / 中华超声影像学杂志

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.

Application of vector flow mapping technique in the assessment of left intraventricular pressure gradients in heart failure patients / 中华超声影像学杂志

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.