Evaluation of diastolic left ventricular relative pressure in patients with type 2 diabetes mellitus by vector flow mapping / 中华超声影像学杂志

Objective:To evaluate the distribution of diastolic left ventricular pressure in patients with type 2 diabetes mellitus (T2DM) by relative pressure imaging (RPI) based on vector flow mapping (VFM), and to explore the clinical risk factors for the diastolic left ventricular pressure distribution.Methods:Thirty patients with T2DM and thirty normal controls were included from August 2020 to July 2021 in Fuwai Central China Cardiovascular Hospital. All selected subjects underwent conventional echocardiography.Left intraventricular pressure difference (IVPD) and left intraventricular pressure gradient (IVPG) were measured using RPI of VFM in isovolumic relaxation (IR), rapid filling (RF), atrial contraction (AC), isovolumic contraction (IC) and rapid ejection (RE) phases. The relationships between IVPD with other parameters were analyzed.Results:①Compared with the control group, E/A, e′, IVPD-IR, IVPG-IR, IVPD-RF, IVPG-RF, IVPD-AC, and IVPG-AC were significantly lower and E/e′ was significantly greater in the T2DM group ( P<0.05). ②IVPD-IR, IVPD-RF, and IVPD-AC were positively correlated with E/A ( r=0.309, P<0.05; r=0.274, P<0.05; r=0.273, P<0.05). IVPD-IR, IVPD-RF, and IVPD-AC were negatively correlated with E/e′ ( r=-0.587, P<0.05; r=-0.273, P<0.05; r=-0.415, P<0.05). IVPD-IR and IVPD-AC were positively correlated with e′ ( r=0.451, P<0.05; r=0.431, P<0.05). ③Multivariable linear regression analysis showed that hemoglobin A 1c (HbA 1c) was an independent risk factor affecting IVPD-IR, IVPD-RF, and IVPD-AC (β=-0.417, P<0.05; β=-0.451, P<0.05; β=-0.460, P<0.05). Conclusions:RPI of VFM can quantitatively evaluate diastolic left ventricular pressure distribution in patients with T2DM. HbA 1c is an independent risk factor affecting IVPD-IR, IVPD-RF, and IVPD-AC.

Application of relative pressure imaging in assessing changes of diastolic left intraventricular pressure in hypertensive patients with different left ventricular configurations / 中华超声影像学杂志

Objective:To investigate the changes of intraventricular pressure differences (IVPDs) and intraventricular pressure gradients (IVPGs) in different diastolic phases of hypertensive patients with different left ventricular configurations by relative pressure imaging (RPI) based on vector flow mapping (VFM), and to explore its diagnostic value for diastolic function in hypertensive patients with different left ventricular configurations.Methods:Totally 180 patients with hypertension were selected from April 2020 to March 2021 in the Outpatient Clinic of the Second Affiliated Hospital of Harbin Medical University. According to the relative wall thickness (RWT) and left ventricular mass index (LVMI), the patients were divided into normal geometry group (NG group, n=62), concentric remodeling group (CR group, n=62) and concentric hypertrophy group (CH group, n=56). Sixty-one healthy volunteers were selected as the control group. Clinical data and echocardiographic parameters were collected and the differences of each parameter among 4 groups were compared. IVPDs and IVPGs in four diastolic phases were obtained by RPI, including isovolumic relaxation (IR), rapid filling (RF), slow filling (SF) and atrial contraction (AC). The differences of IVPDs and IVPGs in each phase of diastole among 4 groups and their correlations with echocardiographic parameters were analyzed, and the diagnostic efficacy of RPI parameters in NG group patients with reduced diastolic function was analyzed by the ROC curve. Results:The absolute values of IVPDs and IVPGs were greater in all subgroups of hypertension than those of the control group at each diastole phase( P<0.001). Pairwise comparisons showed statistically significant differences of IVPDs-IR and IVPGs-IR among 4 groups( P<0.001). They were correlated with E/e′( rs=-0.615, -0.605; all P<0.001). IVPDs-IR and IVPGs-IR had good diagnostic efficacy for the decrease of diastolic function of patients in NG group, the cutoff values were <-0.705 mmHg (AUC=0.935, P<0.001) and <-0.130 mmHg/cm (AUC=0.926, P<0.001). Conclusions:RPI can precisely assess different degrees of diastolic function changes in hypertensive patients with different configurations. IVPDs-IR and IVPGs-IR can be used as potential new indicators for non-invasive early diagnosis of hypertensive patients with reduced diastolic function, which is of great significance for timely clinical intervention and treatment of reversing ventricular remodeling.

The preliminary value of vector flow mapping on assessment of left intraventricular pressure difference in patients with paroxysmal atrial fibrillation / 生物医学工程学杂志

This study aims to explore the intraventricular pressure difference (IVPD) within left ventricle in patients with paroxysmal atrial fibrillation (PAF) by using the relative pressure imaging (RPI) of vector flow mapping (VFM). Twenty patients with paroxysmal atrial fibrillation (PAF) and thirty control subjects were enrolled in the study. Systolic and diastolic IVPD derived from VFM within left ventricle and conventional echocardiographic parameters were analyzed. It was found that the B-A IVPD of left ventricle in PAF patients showed the same pattern as controls-single peak and single valley during systole and double peaks and double valleys during diastole. Basal IVPD was the main component of base to apex IVPD (B-A IVPD). The isovolumetric systolic IVPD was associated with early systolic IVPD, early systolic IVPD was associated with late systolic IVPD, and late systolic IVPD was associated with isovolumic diastolic IVPD (all

Evaluation of diastolic left intraventricular pressure differences in normal adults detected by vector flow mapping / 中华超声影像学杂志

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.

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.

Medición de presiones relativas en aorta torácica y arteria pulmonar de voluntarios sanos y pacientes con Tetralogía de Fallot reparada utilizando la secuencia 4D Flow de resonancia magnética cardíaca / Relative pressure measurement in thoracic aorta and pulmonary artery in healthy volunteers and patients with Tetralogy of Fallot repaired by 4D Flow cardiovascular MRI

Objective. To validate the utility of 4D Blood Flow and Navier-Stokes equations to create relative pressure (RP) maps in the aorta and pulmonary artery (PA) in healthy volunteers and patients with repaired tetralogy of Fallot (TOF). Methods. A 4D flow sequence of whole heart and its major vessels was acquired in 10 healthy volunteers and 6 patients with repaired TOF. The root of the ascending aorta was used as the reference point to calculate RP along five different points of this area. In addition, relative pressure of both right and left PA was measured as correlated to absolute pressure. Results. Patients with repaired TOF showed greater pulmonary artery (PA) relative pressure differences between maximum and minimum values when compared to volunteers (p <0.05). Additionally, aortic relative pressures had an excellent correlation with published data, whether using 4D flow or by catheterization. Conclusions. 4D Flow MRI may represent a new non-invasive and non operator-dependent diagnostic tool in CV disease management.

Objetivo. Utilizar 4D Flow y las ecuaciones de Navier-Stokes para obtener mapas de presiones relativas (PR) en la Aorta y Arteria Pulmonar (AP) de voluntarios y pacientes con Tetralogía de Fallot reparada (TOFr). Métodos. En 10 voluntarios y 6 pacientes con TOFr se adquirió la secuencia 4D flow del corazón y sus principales vasos. La raíz de la Aorta Ascendente se utilizó como referencia para calcular las PR a esta zona en cinco puntos distintos. Además, se midió la PR de la AP derecha e izquierda respecto a la AP. Resultados. Los pacientes con TOFr tuvieron diferencias de PR entre los valores máximos y mínimos más grandes que los voluntarios en la AP (p<0,05). Adicionalmente, las PR de la aorta tuvieron una excelente correlación con datos publicados utilizando 4D flow y mediante cateterización. Conclusiones. 4D Flow podría constituir una nueva herramienta diagnóstica, no invasiva, ni operador dependiente, en el manejo de patologías CV.

The Changes of Plantar Pressure and Pathway of Center of Pressure in Foot during the Gait in Normal Preschool Children with Age

OBJECTIVE: To find out the changes of the plantar pressure distribution of foot and the pathway of center of pressure (COP) in normal preschool children with age. METHOD: Thirty-eight normal children aged 1 to 6 were participated in this study. We divided into three groups according to the age. Foot contact area, pressure of the foot and pathway of COP were measured using F-scan in-shoe measuring system (Tekscan Inc.) during the gait. RESULTS: The ratio of midfoot contact width to forefoot contact width was decreased with age (p<0.05). And the relative pressure of the medial midfoot was decreased with age (p<0.05). In the analysis of COP, the ratio of anteroposterior length of COP to total contact length was significantly increased (p<0.05), and the ratio of mediolateral width of COP to forefoot contact width was tend to decrease. CONCLUSION: We can identify the characteristics and changes of the foot pressure distribution and the pathway of COP in preschool children with normal foot using F-scan system. These quantitative data of foot scan are useful for evaluating the foot pathology in preschool children during the gait.