Wave Peak Velocity Research Articles

Cardiac Structure and Function in 8- to 12-Year-Old Children Following In-Utero Exposure to Preeclampsia (FINNCARE Study).

We evaluated how elevated blood pressure in children exposed to preeclampsia (PE) impacted on their cardiac structure and function, as well as relations with maternal, gestational, and perinatal factors and child body size and composition. A total of 182 PE (46 early-onset preeclampsia) and 85 unexposed (non-PE) children were examined in the FINNCARE study 8 to 12 years after the index pregnancy with echocardiography; office, central, and 24-hour ambulatory blood pressures; and body anthropometrics and composition. PE children had lower right ventricular basal sphericity index (mean difference, -0.26 95% CI, -0.39 to -0.12) and lower mitral lateral E'-wave peak velocity (-1.4 cm/s [95% CI, -2.1 to -0.6]), as well as higher E to E' ratio (0.40 [95% CI, 0.15-0.65]) and indexed tricuspid annular plane systolic excursion (0.03 [95% CI, 0.01-0.05]) compared with non-PE children. These differences were accentuated in early-onset PE children. Left ventricular mass (LVM) or left atrial volume were not different between PE and non-PE children. Lean body mass, body fat percentage, and 24-hour systolic blood pressure were independent predictors of LVM. Lean body mass and body fat percentage were independent predictors of left atrial volume. No significant associations between LVM or left atrial volume and maternal, gestational, or perinatal parameters were found. Preadolescent PE children display a more globular-shaped right ventricle with higher longitudinal systolic displacement as well as mildly altered diastolic indices, with the alterations being pronounced in early-onset preeclampsia. Lean body mass and adiposity are independently related with LVM and left atrial volume, and systolic blood pressure with LVM in both PE and non-PE children. These unfavorable associations indicate remodeling of cardiac structure in young children also reflected in mild functional changes in PE children. URL: https://www.clinicaltrials.gov; unique identifier: NCT04676295.

Statistics at high-altitudes: Relevance for the interpretation of metrics that reveal cardiac morphology and performance.

Survey of four ratio-based metrics, commonly used to evaluate left ventricular performance. The numerator of each ratio is plotted against the corresponding denominator, implying that the slope of the colored line reflects the value of the ratio.9,11 Similar graphs can be constructed for the other cardiac compartments. Data sets obtained at various altitudes and defined with reference to sea level, based on Rao et al.6 Acronyms: E/A unitless ratio of the early (E) and late (A) diastolic wave peak velocities (cm/s); EDD, end-diastolic diameter (mm); EDV, end-diastolic volume (mL); EF, ejection fraction (%); ESD, end-systolic diameter (mm); ESV, end-systolic volume (mL); FS, fractional shortening (%).

Doppler echocardiography for surveillance of acute cardiac allograft rejection: a 28-year single-center experience.

Endomyocardial biopsies (EMB) are recommended for the detection of acute cardiac rejection (ACR) despite limited sensitivity. We report the long-term post-transplant results of Doppler echocardiography as a noninvasive alternative of routine EMB. Two cohorts of heart transplantation (HT) recipients were chronologically defined as follows: the Dual Monitoring Cohort (DMC) from January 1990 to December 1997 included patients who underwent routine EMB and Doppler echocardiography within 24 hours for ACR surveillance; and the "Echo-First Cohort" (EFC), including patients transplanted from January 1998 to December 2018 with Doppler echocardiography as first-line approach for ACR surveillance. Echocardiographic measurements of interest were collected: early diastolic (E) wave peak velocity; pressure half time (PHT) and isovolumetric relaxation time (IVRT). Post-transplant outcomes were reviewed and the Kaplan-Meier approach was used for survival estimates. Inter-operator variability for ultrasound measurements was investigated. Data were collected from medical records from January 2019 to December 2020. A total of 228 patients were included, 99 patients in the DMC and 129 in the EFC. Overall, 5-, 10- and 15-year survival rates were 65.4%, 55.5% and 44.1% respectively, without any significant difference between the two cohorts (log rank test, P=0.71). Echocardiography variables and EMB findings were associated with a mean area under the receiver operating characteristic curve (AUC-ROC) of 0.73 [95% confidence interval (CI): 0.54-0.91], 0.74 (95% CI: 0.54-0.94) and 0.75 (95% CI: 0.57-0.94) respectively for E wave, PHT and IVRT. IVRT and PHT were significantly decreased, and E wave significantly increased, in case of histologically proven ACR. Inter-operator variability was not significant for E wave and IVRT measurements (P=0.13 and 0.30 respectively). Doppler echocardiography as a first-line method for surveillance of ACR did not impair long-term results after HT. These findings suggest that this non-invasive approach might be a reasonable alternative to systematic EMB, limiting risk and improving the quality of life.

Investigation of the influence of sinusoidal internal waves on a SPAR buoy structure

Offshore wind has a great potential as a competitive source of renewable energy, especially in deep waters where wind speeds are more consistent and fewer restrictions apply for running large wind turbines. Previous analyses of Floating Offshore Wind Turbines (FOWTs) mostly considered obvious sources of loading: surface waves, currents, wind and mooring. However, in some deep-water locations, internal waves can occur and these have been shown to significantly affect floating structures. Since the hydrodynamic response of an FOWT governs the structure’s general stability, the aim of this research is to investigate the impact of sinusoidal internal waves on the platform motion of a free-floating SPAR-type cylinder. A potential flow model and Morison’s equation are applied numerically to calculate the forces acting on a free-floating cylinder in an oscillating flow. The commercial Finite Element Analysis software OrcaFlex is verified by the potential flow model of the oscillating flow and is then used to mimic sinusoidal internal waves acting on a free-floating cylinder in a stratified flow. Three different internal wave amplitudes and peak velocities are analysed, and the nine resulting cases are investigated for the oscillating and stratified flow each. It has been found that the pitch rotations of the SPAR cylinder were small (< 0.1°) in all cases and can likely be disregarded. The surge displacements of the free-floating cylinder were substantial in both oscillating and stratified flows, with maximum surge magnitudes of 423m and 120m, respectively. Therefore, significant additional mooring loads due to internal waves could be sustained by SPAR-type FOWTs.

Right and left ventricular structures and functions in acute HFpEF: comparing the hypertensive pulmonary edema and worsening heart failure phenotypes.

Limited data are available on right (RV) and left (LV) ventricular structures and functions in acute heart failure with preserved ejection fraction (AHF-pEF) presenting with hypertensive pulmonary edema (APE) versus predominant peripheral edema (peHF). In a prospective study of consecutive patients with AHF-pEF, 80 patients met inclusion and not exclusion criteria, and underwent echocardiographic and laboratory examination in the emergency ward. The survived (94%) were re-evaluated at the discharge. At admission, systolic, diastolic, pulse blood pressure (BP), and high sensitivity troponin I were higher (all P < 0.05) with APE than with peHF while brain-type natriuretic peptide (BNP), hemoglobin and estimated glomerular filtration rate (eGFR) did not differ between the two phenotypes. LV volumes and EF were comparable between APE and peHF, but APE showed lower relative wall thickness (RWT), smaller left atrial (LA) volume, higher pulse pressure/stroke volume (PP/SV), and higher ratio between the peak velocities of the early diastolic waves sampled by traditional and tissue Doppler modality (mitral E/e', all P < 0.05). Right ventricular and atrial (RA) areas were smaller, tricuspid anular plane systolic excursion (TAPSE) and estimated pulmonary artery peak systolic pressure (sPAP) were higher with APE than with peHF (all P < 0.05) while averaged degree of severity of tricuspid insufficiency was greater with peHF than with APE. At discharge, PP/SV, mitral E/e', sPAP, RV sizes were reduced from admission in both phenotypes (all P < 0.05) and did not differ anymore between phenotypes, whereas LV EF and TAPSE did not show significant changes over time and treatments. In AHF-pEF, at comparable BNP and LV EF, hypertensive APE showed eccentric LV geometry but smaller RV and RA sizes, and higher RV systolic function, increased LV ventricular filling and systemic arterial loads. AHF resolution abolished the differences in PP/SV and LV diastolic load between APE and peHF whereas APE remained associated with more eccentric RV and higher TAPSE.

Echocardiography in Prone Positioned Critically Ill Patients: A Wealth of Information from a Single View

In critically ill patients, standard transthoracic echocardiography (TTE) generally does not facilitate good image quality during mechanical ventilation. We propose a prone-TTE in prone positioned patients, which allows clinicians to obtain a complete apical four-chamber (A-4-C) view. A basic cardiac assessment can be performed in order to evaluate right ventricle function and left ventricle performance, even measuring objective parameters, i.e., tricuspid annular plane systolic excursion (TAPSE); pulmonary artery systolic pressure (PAP), from the tricuspid regurgitation peak Doppler velocity; RV end-diastolic diameter and its ratio to left ventricular end-diastolic diameter; the S’ wave peak velocity with tissue Doppler imaging; the ejection fraction (EF); the mitral annular plane systolic excursion (MAPSE); diastolic function evaluation by the mitral valve; and annular Doppler velocities. Furthermore, by tilting the probe, we can obtain the apical-five-chamber (A-5-C) view, which facilitates the analysis of blood flow at the level of the output tract of the left ventricle (LVOT) and then the estimation of stroke volume. Useful applications of this technique are hemodynamic assessment, titration of fluids, vasoactive drugs therapy, and evaluation of the impact of prone positioning on right ventricle performance and right pulmonary resistances. We believe that considerable information can be drawn from a single view and hope this may be helpful to emergency and critical care clinicians whenever invasive hemodynamic monitoring tools are not available or are simply inconvenient due to clinical reasons.

Echocardiographic Characteristics of Cardiogenic Shock Patients with and Without Cardiac Arrest.

Cardiac arrest (CA) is associated with worse outcomes in patients with cardiogenic shock (CS). To better understand the contribution of CA on CS, we evaluated transthoracic echocardiography (TTE) parameters in CS patients with and without CA. We retrospectively identified CS patients with a TTE performed near cardiac intensive care unit admission between 2007 to 2018. We compared TTE measurements of left ventricular (LV) and right ventricular (RV) function in patients with and without CA. The primary outcome was all-cause in-hospital mortality, as determined using multivariable logistic regression. We included 1085 patients, 35% of whom had CA. Median age was 70 years and 37% were females. CA patients had higher severity of illness, more invasive mechanical ventilation and greater vasopressor/inotrope use. In-hospital mortality was 31% and was higher in CA patients (45% vs. 23%, p <0.001). Although LV ejection fraction (LVEF) was similar (35% vs. 37%, p = 0.05), CA patients had lower cardiac index, mitral valve E wave peak velocity, E/A ratio and E/e' ratio. TTE variables that were associated with hospital mortality varied, among patients with CA, these included measures of RV pressure and function and among patients without CA, these included parameters reflecting LV systolic function. Doppler assessments of RV systolic dysfunction were the strongest TTE predictors of hospital mortality in CS patients with CA, unlike CS patients without CA in whom LV systolic function was more important. This emphasizes the importance of RV assessment for mortality risk stratification after CA.

Predictive power of diastolic parameters on medical cardioversion success in acute atrial fibrillation.

Diastolic function assessment has been reported to provide valuable data in patients with atrial fibrillation (AF). The purpose of this study was to evaluate the effects of diastolic parameters on predicting the effectiveness of medical cardioversion in restoring sinus rhythm among patients with acute AF. 40 non-valvular, new onset AF patients were included. All participants received an intravenous infusion of amiodarone. In patients whom sinus rhythm could not be restored with amiodarone, an electrical cardioversion was performed. Two groups, patients who achieved sinus rhythm with amiodarone (Group-1) and who failed to achieve sinus rhythm with amiodarone (Group-2) were compared with respect to initial echocardiographic measurements. Group-1 patients were younger comparing with Group-2 (mean age; 54.4 ± 13.9 years vs 63.3 ± 10.3 years, p=0.028). Comparing with Group-1, Group-2 patients had; a higher left atrium volume index (17.1 ± 4.8cm3 / m2 vs 22.6 ± 6.6cm3 / m2 , p=0.03); a shorter pulmonary vein S (49.6 ± 3.8cm/sec vs 41.1 ± 3.0cm/sec, p<0.001); and a shorter pulmonary vein D peak velocity (55.9 ± 2.4cm/sec vs 52.3 ± 1.8cm/sec, p<0.001). Moreover, both IVRT and DT were significantly shorter in Group-2, comparing with Group-1 (45.1 ± 2.1 msec vs 51.1 ± 2.5 msec, p<0.001 and 51.3 ± 2.4 msec vs 56.5± 3.2 msec, p<0.001, respectively). The present study revealed that admission pulmonary vein S and D wave peak velocities, IVRT, DT, and Pro-BNP levels could be predictors of failure of medical cardioversion among AF patients.

Correlation between ductus venosus spectrum and right ventricular diastolic function in isolated single-umbilical-artery foetus and normal foetus in third trimester.

BACKGROUNDSingle umbilical artery (SUA) is the most common umbilical cord malformation in prenatal diagnosis. The presence of an SUA can cause blood circulation disorder in the foetus and functional changes of the foetal heart, affecting foetal circulation. The right ventricular diastolic functions in foetuses with isolated SUA and in normal foetuses in the third trimester were evaluated using the spectral Doppler of blood flow in the foetal ductus venosus (DV).AIMTo evaluate the right ventricular diastolic functions in foetuses with isolated SUA and in normal foetuses in the third trimester.METHODSColour Doppler was used to measure the spectrum of foetal DV and tricuspid orifice in 34 foetuses with isolated SUA aged 28-39 wk and in age-matched healthy controls. The DV flow velocities and velocity ratios were measured. The early passive/late active (E/A) ratio at the tricuspid orifice and tissue Doppler Tei index of the foetal right ventricular in the two groups were also measured.RESULTSDuring the third trimester, the isolated SUA group showed a lower ‘a’-wave peak velocity in the DV than the control group (P < 0.05). The correlations between the velocity ratios and E/A ratio at the tricuspid orifice in the two groups were analysed, and the correlation between the ventricular late diastolic velocity/ventricular diastolic peak flow velocity and E/A ratios was the best (R2 of the isolated SUA group: 0.520; R2 of the control group: 0.358). The correlations between the velocity ratios and tissue Doppler Tei index of foetal right ventricular in the two groups were analysed, and the correlation between the pulsatility index for veins (PIV) and tissue Doppler Tei index ratios was the best (R2 of the isolated SUA group: 0.865; R2 of the control group: 0.627).CONCLUSIONIn the isolated SUA group, the atrial systolic peak velocity ‘a’ decreased, and this finding might be related to the changes in foetal cardiac functions. The ratio of ventricular late diastolic velocity to ventricular diastolic peak flow velocity was closely related to the E/A ratio at the tricuspid valve and can be used to identify changes in the right ventricular diastolic functions of isolated SUA and healthy foetuses. PIV was closely related to the tissue Doppler Tei index of the foetal right ventricular and can be used to identify the right ventricular overall functions of isolated SUA and healthy foetuses.

Accurate prediction of left ventricular diastolic dysfunction in 2D echocardiography using ensemble of deep convolutional neural networks

Abstract Introduction Deep convolutional neural networks (CNNs) have been shown to be reliable in evaluating geometrically assessed systolic heart function, however, studies evaluating diastolic heart function, which reflects hemodynamic status, are scarce. This study presents a novel CNNs approach for recognition and evaluation of different diastolic left ventricular (LV) function measurements. Purpose To create a new CNNs approach in the assessment of LV diastolic function and compare the results with clinicians' measurements. Methods A total of 4586 2D echocardiographic images were extracted from the studies of 330 patients referred with varying indications. The ensemble of four CNNs was trained (80/20% training/validation patient split) for the assessment of transmitral inflow (E and A wave peak velocities), mitral septal and lateral annular velocities (e'), tricuspid regurgitation systolic velocity (Vmax) and detection the left atrial endocardium in apical four-chamber views. Additionally, E/A ratio, average E/e' ratio and left atrial volume index (LAVi) values were calculated for the evaluation of diastolic dysfunction according to the 2016 ASE/EACVI recommendations. CNNs performance in detecting diastolic dysfunction was compared to expert cardiologists on a set of 20 separate cases. Results Study results on the validation data showed that CNNs accurately predicted peak E/A ratio, average E/e' ratio (R2=0.88 and R2=0.89, respectively) and tricuspid regurgitation Vmax (R2=0.82). Figure 1 illustrates different functional LV measurements among the obtained echocardiographic images. Regarding the geometrical assessment of diastolic function, the segmentation model traced the left atrial endocardial border (intersection over union = 0.94) and subsequently was used in predicting the LAVi (R2=0.92). The ensemble of four CNNs had the area under the ROC curve of 0.93 for the detection of diastolic dysfunction when compared to expert cardiologists. Conclusion Deep CNNs demonstrate the capacity to detect peak velocities across different Doppler imaging modes and delineate left atrial endocardium border while using a relatively small dataset. Combining multiple CNNs has the potential of performing an accurate assessment of the diastolic LV function. Funding Acknowledgement Type of funding source: None

Assessment of left ventricular energy loss using vector flow mapping in patients with stages 1\u20133 chronic kidney disease

BackgroundPatients with chronic kidney disease (CKD) experience abnormality of intracardiac blood flow status during early-stages of disease. Left ventricular energy loss (EL) derived from vector flow mapping (VFM) represents fluid energy lost as heat in left ventricle and had been used to detect intracardiac blood flow efficiency. We aimed to evaluate the left ventricular EL in stage 1–3 CKD patients, and explored whether hypertension, a main cardiovascular risk, deteriorate the abnormality of intracardiac blood flow status.MethodsTransthoracic echocardiography was performed in 41 controls and 48 patients with stages 1–3 CKD. CKD patients consisted a subgroup with no hypertension, a subgroup with well-controlled hypertension and a subgroup with poorly controlled hypertension. The EL were calculated in the left ventricle using VFM analysis from the apical 3-chamber view. Furthermore, the correlation and stepwise multiple regression analysis were used to explore the potential independent predictors of left ventricular EL.ResultsCompared with controls, stage 1–3 CKD patients showed increased left ventricular EL during total diastole, late diastole, total systole, isovolumic contraction and ejection. CKD patients with poorly controlled hypertension had higher left ventricular EL compared to the other CKD subgroups. Additionally, the ratio of mitral early filling wave peak velocity and early mitral annular peak velocity on septal side, mitral early filling wave peak velocity, and left ventricular mass index were independent predictors of the diastolic EL; whereas systolic blood pressure and left ventricular mass index were independent predictors of the systolic EL.ConclusionsLeft ventricular EL was a useful echocardiographic parameter to evaluate the impaired intracardiac blood flow efficiency in patients with stages 1–3 CKD. Hypertension was a crucial contributor for intracardiac blood flow abnormality. This study might provide valuable clinical data to discern cardiac dysfunction and reduce the cardiovascular risk in early-stage CKD.

Low Frequency Wave Loads and Damping of Four MODUs in Severe Seastates With Current

Abstract Model tests have been performed with four mobile offshore drilling units (MODUs) with the aim of identifying wave drift forces and low-frequency damping. The MODUs configuration is different, namely on the number and diameter of columns; therefore, the sample is representative of many of the existing concepts. The model scale is the same as well as the wave and current conditions. The experimental program includes irregular waves with systematic variations of the significant wave height, wave peak period, current velocity, and vessel heading. A nonlinear data analysis technique (cross bi-spectral analysis) is applied to identify the surge and sway quadratic transfer functions (QTFs) of the slowly varying excitation, together with the linearized low-frequency damping. The paper also presents a semi-empirical formula developed in the scope of the EXWAVE JIP to correct potential flow mean wave drift force coefficients of Semis in high seastates with current. The empirical QTFs are then compared with numerical predictions. Comparisons with potential flow coefficients lead to conclusions on the role of viscous drift. The semi-empirical formula is assessed based on comparisons with test results and concluded that it provides a significant improvement compared to potential flow predictions.

P1503Decrement of vortex formation time during dobutamine stress echo

Abstract Background Vortex Formation Time (VFT) is a novel index of systolic and diastolic function which may be also affected by left ventricular geometry, but has never been evaluated during dobutamine stress echocardiography (DSE) protocols. We sought to investigate the changes in VFT during DSE protocol. Methods DSE was performed in 50 consecutive patients. Patients with poor acoustic window, atrial fibrillation, cardiac valve disease or pacemaker were excluded. Apical four and apical two chamber views were acquired and the following parameters were calculated off- line without knowledge of DSE result both at rest and at peak: left ventricular end-diastolic and end-systolic volume, stroke volume, ejection fraction, stroke work, e and a wave peak velocity and VTI, TDI-derived mitral annular early diastolic velocity at the lateral wall and mitral valve diameter. VFT calculated according to the following equation: VFT = [4 *(1 − β) * α3 * EF]/π, where α = (LVEDV/α3)(1/3) and is affected by ventricular geometry and β = VTIa-wave/(VTIe wave + VTIa-wave) reflecting the atrial filling fraction. Results Median age of the study population was 61 [53–72], 38 men (76%) and 13 (26%) had an old myocardial infarction. Fifteen patients (30%) were positive for myocardial ischemia during DSE. At rest, median LVEDV was 121.5ml (101.8–148.0), median EF (%): 59.9 [54.4–64.1], median atrial filling fraction: 0.43 [0.40–0.48], median mitral valve diameter (cm): 2.8 [2.6–3.0] and median VFT: 2.44 [1.74–3.10]. At peak, median LVEDV was 102.0ml [86.4–122.3] median EF (%) 65.7 [58.8–69.8], median atrial filling fraction: 0.67 [0.59–0.73], median mitral valve diameter (cm): 2.7 [2.5–2.9] and median VFT: 1.45 [1.05–1.88]. VFT decreased in the whole population (Wilcoxon rank test, p&lt;0.001) (figure 1A) and when patients were stratified according to test result. Median VFT decrease was significantly higher in patients with a positive DSE (50%) than in patients with negative DSE (39%) (Mann- Whitney U test, p=0.048) (figure 1B). Figure 1 Conclusion The VFT decreased significantly during DSE and most prominently in patients with ischemic response. This may indicate the deterioration of left ventricular diastolic or systolic function as well as change in left ventricular geometry during DSE protocol.

Assessment of Aortic Root Mechanics in Hypertensive Patients by Speckle Tracking Echocardiography

Objectives: Hypertension is a major risk factor for several cardiovascular diseases, including stroke, atherosclerosis and coronary heart disease. Remodeling of the aortic root may be expected to occur in hypertensive subjects as a result of increased stress on the aortic wall due to the repeated hemodynamic overload. Two-dimensional speckle tracking echocardiography is a promising new imaging modality. The aim of this study is to assess aortic root mechanics in relation to left ventricular mechanics in hypertensive patients by speckle tracking echocardiography. Methods: The study included 50 individuals, 30 patients with hypertension compared with 20 age and sex matched healthy volunteers as control group. For both groups, conventional echo was done and speckle tracking echocardiography of the LV including longitudinal, circumferential, radial strain, LV rotation and the longitudinal strain of the ascending aorta and aortic distensibility were measured. Results: Aortic longitudinal strain of both anterior and posterior walls, andalso LV longitudinal peak systolic strain were lower significantly in patient group, and also in the same group, the apical rotation was higher than control; aortic longitudinal strain was negatively correlated with E/E, and LV global longitudinal strain was correlated positively with septal annular E wave peak velocity and with aortic distensibility. Conclusion: Hypertension significantly lowers ascending aortic longitudinal strain and the changes are correlated significantly with LV longitudinal systolic function and with echo parameters of elevated LV filling pressure.

Correlation between Left Ventricular End Diastolic Pressure and Torsion Dynamics in Patients with Diastolic Dysfunction, Speckle Tracking Imaging Study

Background: Invasive measuring of LV end diastolic pressure (LVEDP) provides reliable assessment of LV diastolic dysfunction, but its invasive nature limits its use in daily practice. Accurate noninvasive assessment of LV diastolic dysfunction is highly desirable, and the relationship between the degree of LVEDP and LV torsion dynamics assessed by 2D speckle tracking is not clearly assessed; here in our study we aimed to assess the relation between the degree of LVEDP and torsion dynamics of left ventricle. Methods: The study included sixty patients divided equally into 3 groups according to the degree of LVEDP, group I: 18 mmHg; complete conventional echo-Doppler study includes also annular septal E wave peak velocity, E/E’ ratio and 2D-speckle tracking including parameters of LV global longitudinal strain (GLS), peak and time to peak of twist ratio (TR & TT respectively), peak and time to peak of untwist ratio (UTR & UTT respectively). Results: There was significant progressive decrease in GLS with progressive increase in LVEDP from I to III. Untwist ratio increased in group II and decreased in significant degree in group III; Twist ratio did not differ with different grades of LVEDP. LA diameter and E/E’ increase from group I to III. The LVEDP is negatively correlated with the UTR and GLS is positively correlated with UTT, E/E & LA diameter. The E/E’ ratio is correlated negatively with the UTR, GLS and positively with LVEDP & UTT and LA diameter. Conclusions: Noninvasive assessment of LV torsion and untwisting was feasible in patients with various grades of LVEDP and diastolic dysfunction; the peak untwist ratio increased in mild degree of increased LVEDP then decreased again with more increase in LVEDP; LVEDP wasnegatively correlated with the peak untwist ratio and GLS was positively correlated with UTT and E/E’.

Dynamic Response of Lunar Soil Caused by Landing Impact

In recent years, there is an increasing interest on lunar exploration and future utilization of lunar resources. Technology of landing is a key in order to establish frequent access to the lunar surface. For a lunar lander, one of the major tasks is to accurately determine the loads and energy absorption capability during the landing event. On the other hands, it should be paid special attention on the study of wave propagation phenomenon in lunar soil and its dynamic response and dissipated energy by the lunar soil. A series of model tests for the simulated lunar soil model with plane and slope are conducted. The model tests are performed to study on the regularity of wave propagation and its attenuation in lunar soil. The waveform of acceleration, velocity and earth pressure in the model are observed. The research focuses on the analysis of the phenomenon through numerical methods. The wave propagation characteristics of the lunar soil model with plane and slope is assessed by means of dynamic FEM analyses in three dimensions. The analysis is obtained in the time domain and allows the consideration of multiple wave reflections between layers. It is concluded that the wave field propagation in lunar soil during landing impact mainly shows Rayleigh wave along axial of impact pads, and repeatedly superimposing occur between impact pads. The predominant frequency of the landing impact is over 100 Hz. The response is quickly attenuated in lunar soil and its propagation distance is very limited. Moreover, according to the numerical results and the model test results, it can be found that a small input wave velocity (< 1 m/s) has a great impact on the maximum acceleration and displacement. Furthermore, when it reaches a certain value, the maximum acceleration and displacement reach the maximum value. The plastic strain zone increases rapidly with the increasing input wave peak velocity, when the plastic strain is > 0.05, and when input wave velocity is 4 m/s, the ground floor of the landing pad is in plastic.

Looking for Perfection in the Evaluation of Mitral Regurgitation

Background: Currently, there is no single echocardiographic parameter for assessing the severity of mitral regurgitation. Two conceptually similar methods have been published. One method is the mitral valve to LVOT velocity time integral ratio (MOTVTI), and the other the mitral E wave peak velocity to LVOT velocity time integral ratio (EVTI). Objectives: Our goals were to compare the ability of both methods to diagnose severe mitral regurgitation and establish the best cutoff points for the diagnosis. Methods: We included patients with and without mitral regurgitation. The area under the ROC curve for MOTVTI and EVTI was analyzed to compare their diagnostic ability of both methods and estimate the best diagnostic cutoff points. Results: A total of 135 patients were included in the study, 51 with various degrees of mitral regurgitation and the rest as controls. Patients with severe mitral regurgitation had an effective regurgitant orifice area of 0.73±0.34 cm2, vena contracta of 8.3±2.2 mm and regurgitant volume of 99±42 ml. The analysis showed an area under ROC curve of 0.83 (95% CI: 0.75 to 0.89) for MOTVTI and 0.92 (95% CI: 0.86 to 0.96) for EVTI, without significant differences. The best cutoff point was> 1.84 for MOTVTI (sensitivity 80%, specificity 94%) and >6.25 for EVTI (sensitivity 100%, specificity 79%). Conclusions: Both methods are useful for the diagnosis of severe MR and have similar diagnostic capacity. The best cutoff points differ from those originally published.

Pneumatocysts provide buoyancy with minimal effect on drag for kelp in wave-driven flow

Many seaweeds have buoyant gas-filled bladders (pneumatocysts) that hold fronds upright in the water column and enhance their access to light for photosynthesis. However, ambient water currents bend flexible seaweeds, pushing fronds closer to the substratum where light is lower, so the hydrodynamic drag on pneumatocysts may counteract their buoyancy in flowing water. The effects of pneumatocysts on frond hydrodynamic drag were investigated in this study, as well as how the positions of pneumatocysts along fronds affect their motion and height in wave-driven water flow. The kelp Egregia menziesii was used as a model organism because it is abundant on wave-swept rocky shores and because our field surveys revealed that this species shows great variation in pneumatocyst size, number, and location on fronds. In laboratory towing-tank studies, it was found that drag on pneumatocysts was reduced when they were bent over by flowing water. The drag due to pneumatocysts was small compared to the drag on a whole frond. At flow speeds up to 0.58ms−1, the buoyant force exerted by a pneumatocyst was greater than the drag it experienced. In wave-tank experiments using models of fronds with pneumatocysts at different positions, the pneumatocysts were most effective at lifting fronds high in the water column when they were located at the distal tips of the fronds, both in small and large waves. However, if fronds had pneumatocysts that were not at the tip, an increase in the peak velocities of waves led to an increase in the heights of the fronds in the water column. In the field, pneumatocysts did not affect the back-and-forth horizontal motion of E. menziesii exposed to waves, but fronds with pneumatocysts were higher in the water column than fronds with no pneumatocysts, even when the number of pneumatocysts on a frond was low. Our results indicate that pneumatocysts can exhibit great variability in size, number, and location with only a small effect on hydrodynamic forces on a kelp, that pneumatocysts at frond tips are most effective at holding kelp high in the water column, but that only a few pneumatocysts at any location along a frond can enhance the frond's height in waves.

Assessment of fetal myocardial performance index in women with pregestational and gestational diabetes mellitus.

Fetal cardiac left ventricular function in pregnant women with pregestational or gestational diabetes mellitus was investigated by exploring fetal myocardial performance index (MPI) and E wave/A wave peak velocity (E/A) ratio. Seventy pregnant women with either pregestational or gestational diabetes mellitus and with no other systemic or pregnancy related disorders were compared with 70 gestational age matched healthy controls by means of fetal left ventricular MPI and E/A ratio. Opening and closing clicks of the mitral and aortic valves were used to define the three time periods: ejection time (ET), isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT), which were employed in the calculation of MPI (MPI = [ICT + IRT]/ET). Statistical analyses were conducted using receiver operating characteristic analysis and independent two-sample t, Mann-Whitney U and chi-square tests. Fetal left ventricular MPI values were significantly higher in the diabetic group compared with controls (0.56 ± 0.09 vs 0.36 ± 0.04, P < 0.001), whereas E/A ratio was lower (0.66 ± 0.11 vs 0.69 ± 0.09, P = 0.049). The adverse perinatal outcome rate was also higher in the diabetic group. Receiver operating characteristic analysis revealed > 0.39 as the optimal cut-off level for MPI in perinatal adverse outcome prediction (sensitivity: 90.9%, specificity: 47.7%, area under the curve: 0.690, 95% confidence interval: 0.598-0.782, P < 0.001). We conclude that fetuses of diabetic mothers have significant left ventricular systolic and diastolic dysfunction. MPI may be used in the prediction of adverse perinatal outcome in diabetic pregnancies.

Myocardial Function Pre- and Post-Fetal Endoscopic TrachealOcclusion (FETO) in Fetuses with Left-Sided Moderate to Severe Congenital Diaphragmatic Hernia.

FETO was performed at 32.5 (SD 2.4) weeks of gestation. There was no statistically significant change in myocardial function in fetuses treated by FETO except a slight prolongation of the ICT of the left ventricle in PW-TDI. The myocardial function of fetuses with CDH pre- and post-FETO and fetuses with CDH without FETO was comparable to that of healthy controls. Conclusion In our series FETO did not affect myocardial function in fetuses with left-sided CDH. Although ventricular preload increases, FETO seems to have no short-term impact on fetal myocardial performance.