Doppler Measurements Research Articles

Right ventricular strain by speckle tracking echocardiography in patients with systemic scleroderma and absence of pulmonary hypertension

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In patients with scleroderma the morphological remodeling and alteration of right ventricular (RV) function begins even before the setting of pulmonary artery hypertension (PAH). These alterations are associated with worse outcomes and high mortality rate as 30% of deaths are attributed to cardiovascular causes followed by respiratory causes (17%). Purpose Early detection of RV dysfunction is possible using advanced imaging techniques and can lead to specific therapeutic management before installation of PAH and clinical signs and symptoms of heart failure . Purpose of this study is to evaluate new indices, based on speckle tracking echocardiography, for identification of subclinical RV systolic failure. Methods Thirty (30) scleroderma patients without any signs or symptoms of PAH and forty (40) healthy subjects were included in the present study. Two-dimensional echocardiography (2DE) and two-dimensional speckle-tracking echocardiography (2DSTE) were performed. All the usual 2DE, Doppler and tissue Doppler imaging measurements were obtained for the evaluation of RV function. Moreover, TAPSE, maximum systolic myocardial velocity from TDI of lateral tricuspid valve annulus (SRV), auto RV global longitudinal strain (aRVGLS) and auto RV free wall longitudinal strain (aRVFWLS) by 2DSTE were measured. aRVGLS and aRVFWLS are new indices, with appropriate RV function echo logistics in new technology echo systems, independent from known manual measurements. Results In scleroderma patients significantly higher systolic pulmonary artery pressure was recorded, although it remained within normal limits in both groups (24.6+-5.4mmHg vs 19.2+-5.9 mmHg) . Scleroderma patients had significant decreased RV systolic function with significantly lower TAPSE and SRV. Both aRVGLS and aRVFWLS were also lower in scleroderma patients compared to the control group (−18.6+-2.7 vs −23.1+-2.3 % and −25.4+-3.1 vs −26.4+-2.2 % respectively). aRVGLS was the best significant predictor of early RV systolic impairment in patients with scleroderma.The difference in aRVFWLS was not significant. Conclusions Scleroderma is a severe systematic disease associated with high mortality rates. RV remodeling, dysfunction, and progressive pulmonary artery hypertension are among the most important internal organ manifestations of this disease. Early detection of RV dysfunction before installation of pulmonary hypertension is possible by 2DSTE, and may be helpful to guide further therapy in these patients.

A systematic review and meta-analysis of the role of Doppler ultrasonography of the superior mesenteric artery in detecting neonates at risk of necrotizing enterocolitis.

The role of postnatal Doppler measurements of the superior mesenteric artery (SMA) in detecting neonates at risk of necrotizing enterocolitis (NEC) remains uncertain; therefore, we systematically reviewed and meta-analyzed the existing evidence regarding the usefulness of SMA Doppler measurements in detecting neonates at risk for NEC. We used the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, and we included studies which reported the following Doppler ultrasonography indices: peak systolic velocity, end-diastolic velocity, time average mean velocity, differential velocity, pulsatility index (PI) and resistive index. Eight studies were eligible for inclusion in the meta-analysis. Evidence suggested that, during the first postnatal day, neonates who developed NEC had a significantly higher peak systolic velocity (mean difference of 2.65cm/s (95% confidence interval [CI] 1.23, 4.06, overall effect Z=3.66, P<0.001)), higher PI (mean difference of 1.52 (95% CI 0.00, 3.04, Z=1.96, P=0.05)) and higher resistive index (mean difference of 1.09 (95% CI 0.59, 1.60, Z=4.24, P<0.001)), compared to neonates who did not develop NEC. However, our findings do not support a strong association between the Doppler ultrasound indices and development of NEC at the time of disease onset. This meta-analysis suggests that first postnatal day SMA Doppler parameters, namely peak systolic velocity, PI and resistive index, are higher in neonates who develop NEC. On the other hand, the aforementioned indices are of uncertain significance once the diagnosis of NEC has been established.

Effect of Maternal Intravenous Hydration in Management of Oligohydramnios and The Changes in the Fetal Doppler

Background and aim: Oligohydramnios is linked to different fetal and maternal conditions. Maternal hydration improves amniotic fluid content, because it promotes uteroplacental perfusion. The current work aimed to determine the results of intravenous hydration on the amniotic fluid index (AFI) and Doppler measurements of uteroplacental blood circulation during pregnancy with the third trimester oligohydramnios.&#x0D; Patients and methods: The current including 50 pregnant women in their third trimester with oligohydramnios. They were selected from the outpatient clinic at Al-Azhar University Hospitals. All were submitted to clinical evaluation by history and examination, followed by abdominal ultrasound and intravenous hydration therapy. Values before and after hydration were compared, delivery mode and fetal outcome were documented.&#x0D; Results: Maternal age was 30 ± 2.28. The majority of them were multigravida (58.0%) and higher percentage were multiparous (70.0%). The GA at delivery ranged between 32 and 37 weeks of gestation. There was a significant reduction of pulse, mean arterial pressure, temperature, hematocrit after hydration than before hydration. The birth weight ranged between 2765 and 3654 g. AF volume, AMF and uterine artery PI were significantly increased while umbilical artery PI was statistically decreased after hydration that corresponding values before hydration. The mode of delivery was normal vaginal delivery among 34% and cesarean section among 66.0% and the mean Apgar score was 7.8±1.9 and 8.9±0.87 at the first and fifth minutes, respectively.&#x0D; Conclusion: Intravenous maternal hydration therapy was safe and effective in terms of improvement of amniotic fluid index in pregnant females with isolated oligohydramnios in the third trimester. It enhanced the amniotic fluid volume and AFI in females with oligohydramnios.

Impact of dapagliflozin on cardiac remodelling in patients with chronic heart failure: The DAPA-MODA study.

Dapagliflozin improves the prognosis of patients with heart failure (HF), regardless of left ventricular ejection fraction (LVEF). However, its effect on cardiac remodelling parameters, specifically left atrial (LA) remodelling, is not well established. The DAPA-MODA trial (NCT04707352) is a multicentre, single-arm, open-label, prospective and interventional study that aimed to evaluate the effect of dapagliflozin on cardiac remodelling parameters over 6 months. Patients with stable chronic HF receiving optimized guideline-directed therapy, except for any sodium-glucose cotransporter 2 inhibitor, were included. Echocardiography was performed at baseline, 30 and 180 days, and analysed by a central core-lab in a blinded manner to both patient and time. The primary endpoint was the change in maximal LA volume index (LAVI). A total of 162 patients (64.2% men, 70.5 ± 10.6 years, 52% LVEF >40%) were included in the study. At baseline, LA dilatation was observed (LAVI 48.1 ± 22.6 ml/m2 ) and LA parameters were similar between LVEF-based phenotypes (≤40% vs. >40%). LAVI showed a significant reduction at 180 days (-6.6% [95% confidence interval -11.1, -1.8], p = 0.008), primarily due to a decrease in reservoir volume (-13.8% [95% confidence interval -22.5, -4], p = 0.007). Left ventricular geometry improved with significant reductions in left ventricular mass index (-13.9% [95% confidence interval -18.7, -8.7], p < 0.001), end-diastolic volume (-8.0% [95% confidence interval -11.6, -4.2], p < 0.001) and end-systolic volume (-11.9% [95% confidence interval -16.7, -6.8], p < 0.001) at 180 days. N-terminal pro-B-type natriuretic peptide (NT-proBNP) showed a significant reduction at 180 days (-18.2% [95% confidence interval -27.1, -8.2], p < 0.001), without changes in filling Doppler measures. Dapagliflozin administration in stable out-setting patients with chronic HF and optimized therapy results in global reverse remodelling of cardiac structure, including reductions in LA volumes and improvement in left ventricular geometry and NT-proBNP concentrations.

Evaluation of second trimester uterine artery doppler indices in women diagnosed with COVID-19 during the first trimester of their pregnancy.

This study aimed at evaluating the hypothesis that 6-14 months pregnant women diagnosed with COVID-19 may have abnormal placental function detectable by increased uterine artery Doppler indices in the second trimester and whether these women could benefit from treatment.A total of 63 women were diagnosed with COVID-19 during the first trimester of their pregnancy and 68 healthy women were involved according to the exclusion criteria. In both groups, Doppler measurements were performed for the determination of high-risk pregnancy by increased uterine artery Doppler indices in the second trimester.It was observed that uterine artery Doppler indices (PI and RI) were significantly increased in second trimester women with COVID-19 infection compared to those without COVID-19. Furthermore, the number of women with a PI value exceeding the 95th percentile and the number of patients with early diastolic notch were higher in the COVID group compared to the control group.Doppler Ultrasound measurement may be a potential method for the management of high-risk pregnancies after asymptomatic/mild COVID-19 infection.

Measurement of Third-Trimester Uterine Artery Doppler for Evaluation of Maternal Postpartum Outcome among Patients with Severe Pre-Eclampsia

Measurement of Third-Trimester Uterine Artery Doppler for Evaluation of Maternal Postpartum Outcome among Patients with Severe Pre-Eclampsia

Doppler wind measurements in Neptune’s stratosphere with ALMA

Context. Neptune’s tropospheric winds are among the most intense in the Solar System, but the dynamical mechanisms that produce them are still unclear. Measuring wind speeds at different pressure levels may help shed light on the atmospheric dynamics of the planet. Aims. The goal of this work is to directly measure winds in Neptune’s stratosphere with ALMA Doppler spectroscopy. Methods. We derived the Doppler lineshift maps of Neptune at the CO(3-2) and HCN(4-3) lines at 345.8 GHz (λ ∼ 0.87 mm) and 354.5 GHz (0.85 mm), respectively. For that purpose, we used spectra obtained with ALMA in 2016 and recorded with a spatial resolution of ∼0.37″ on Neptune’s 2.24″ disk. After subtracting the planet’s solid rotation, we inferred the contribution of zonal winds to the measured Doppler lineshifts at the CO and HCN lines. We developed an MCMC-based retrieval methodology to constrain the latitudinal distribution of wind speeds. Results. We find that CO(3-2) and HCN(4-3) lines probe the stratosphere of Neptune at pressures of 2−1.8+12 mbar and 0.4−0.3+0.5 mbar, respectively. The zonal winds at these altitudes are less intense than the tropospheric winds based on cloud tracking from Voyager observations. We find equatorial retrograde (westward) winds of −180−60+70 m s−1 for CO, and −190−70+90 m s−1 for HCN. Wind intensity decreases towards mid-latitudes and wind speeds at 40°S are −90−60+50 m s−1 for CO and −40−80+60 m s−1 for HCN. Wind speeds become 0 m s−1 at about 50°S. We find that the circulation reverses to a prograde jet southwards of 60°S. Overall, our direct stratospheric wind measurements match previous estimates from stellar occultation profiles and expectations based on thermal wind equilibrium. Conclusions. These are the first direct Doppler wind measurements performed on the Icy Giants, opening up a new method for the study and monitoring of their stratospheric dynamics.

Coronary Microvascular Disease in Contemporary Clinical Practice.

Coronary microvascular disease (CMD) causes myocardial ischemia in a variety of clinical scenarios. Clinical practice guidelines support routine testing for CMD in patients with ischemia with nonobstructive coronary artery disease. Invasive testing to identify CMD requires Doppler or thermodilution measures of flow to determine the coronary flow reserve and measures of microvascular resistance. Acetylcholine coronary reactivity testing identifies concomitant endothelial dysfunction, microvascular spasm, or epicardial coronary spasm. Comprehensive testing may improve symptoms, quality of life, and patient satisfaction by establishing a diagnosis and guiding-targeted medical therapy and lifestyle measures. Beyond ischemia with nonobstructive coronary artery disease, testing for CMD may play a role in patients with acute myocardial infarction, angina following coronary revascularization, heart failure with preserved ejection fraction, Takotsubo syndrome, and after heart transplantation. Additional education and provider awareness of CMD and its role in cardiovascular disease is needed to improve patient-centered outcomes of ischemic heart disease.

IS HOME BLOOD PRESSURE MONITORING USEFUL IN THE DIAGNOSIS AND MANAGEMENT OF REFRACTORY HYPERTENSION?

Objective: Refractory hypertension (RefHT) is defined as uncontrolled blood pressure (BP) despite the use of 5 or more antihypertensives including a long-acting thiazide diuretic and a mineralocorticoid receptor antagonist. It is a subgroup of resistant hypertension (RHT) with recent definition and behavior of extreme severity and refractoriness to treatment. Among resistant hypertensives, the use of ABPM is mandatory, and it has already been shown that HBPM is a good alternative in the follow-up of these patients. Design and method: Cross-sectional study of a historical cohort of patients with RHT. A total of 354 patients (23.9% male; mean age 60.4 ± 11.1 years old) were submitted to 24-hour ABPM and 5-day HBPM (triplicate morning and evening measurements). All underwent a standardized protocol for assessment of cardiovascular risk, sociodemographic and anthropometric data, laboratory evaluation (metabolic profile and renal function), transthoracic Doppler echocardiography and measurement of pulse wave velocity (PWV). The prevalence of refractory hypertension diagnosed by office BP, HBPM and ABPM were calculated. Sensitivity, specificity, predictive values, and likelihood ratios for HBPM were also calculated. Agreement between the procedures was evaluated using kappa coefficients and the Bland–Altman method. Results: The prevalence of refractory hypertension was 20.3% by ABPM and 18.9% by HBPM. Compared to resistant ones, refractory hypertensives diagnosed by HBPM are younger, with a higher prevalence of heart failure and higher levels of albuminuria. In turn, patients with RefHT diagnosed by ABPM are also younger, but they have a higher prevalence of stroke and previous cardiovascular disease, in addition to higher albuminuria. HBPM overestimated systolic BP by 11.2 ± 18.4 mmHg (correlation coefficient = 0.63; Bland-Altman coefficient = 37) and diastolic BP by 2.4 ± 9.2 mm Hg (correlation coefficient = 0.80; Bland-Altman coefficient = 18). The specificity, sensitivity, and positive and negative predictive values of HBPM in detecting RefHT diagnosed by ABPM were 88%, 98%, 97%, and 94%. The kappa coefficient showing excellent agreement (kappa = 0.884). Conclusions: HBPM presented good agreement with ABPM and can be used as a diagnostic method of refractory hypertension.

Estimation of Mouse Carotid Arterial Wall Shear Stress Using High-Frequency Ultrasound Imaging.

Wall shear stress (WSS) is a crucial hemodynamic factor that promotes atherosclerosis (plaque) development in arteries; although the relationship between WSS and arterial atherosclerosis has been explored in many animal studies, it is not fully understood. No suitable tool, however, exists for rapidly estimating dynamic WSS in small-animal studies. This study proposes a 40-MHz high-frequency ultrasound (HFUS) imaging system for dynamic WSS estimation based on mouse carotid artery blood flow velocity gradient measurements by vector Doppler imaging (VDI). Aliasing reduces the accuracy of Doppler measurements, which can be prevented by increasing the imaging frame rate. Conventionally, imaging is performed at two tilted angles by alternating between the angles; in the proposed method, the frame rate was doubled by imaging at each tilted angle sequentially and by then temporally aligning the sequences based on pulsatile flow characteristics. Velocity estimation using this method had low errors for both a steady-flow straight-tube and pulsatile flow 60%-stenosis phantom. The method was tested for wild-type (WT) C57BL/6 mice at 16 weeks old and apolipoprotein E knockout (ApoE KO) mice at 16 and 24 weeks old; differences in time-averaged and oscillatory WSS were observed, and histology confirmed that the 24-week ApoE KO mice with the highest oscillatory WSS had the greatest plaque formation. The proposed HFUS WSS imaging method can predict the location and extent of plaque development; thus, this method is useful for small-animal studies investigating the WSS effect on atherosclerotic plaque development.

Development of Ultrasound Phantom Made of Transparent Material: Feasibility of Optical Particle Image Velocimetry.

The need for ultrasound flow phantoms to validate ultrasound systems requires the development of materials that can clearly visualize the flow inside for measurement purposes. A transparent ultrasound flow phantom material composed of poly(vinyl alcohol) hydrogel (PVA-H) with dimethyl sulfoxide (DMSO) and water solution manufactured using the freezing method and mixed with quartz glass powder to exhibit scattering effects is proposed. To achieve transparency of the hydrogel phantom, the refractive index (RI) was changed to match that of the glass by modifying the PVA concentration and the ratio of DMSO to water in the solvent. The feasibility of optical particle image velocimetry (PIV) was verified by comparing an acrylic rectangular cross-section channel with a rigid wall. After the feasibility tests, an ultrasound flow phantom was fabricated to conduct ultrasound B-mode visualization and Doppler-PIV comparison. The results revealed that the PIV measured through PVA-H material exhibited 0.8% error in the measured maximum velocity compared with PIV through the acrylic material. B-mode images are similar to real tissue visualization with a limitation of a higher sound velocity, when compared with human tissue, of 1792 m/s. Doppler measurement of the phantom revealed approximately 120% and 19% overestimation of maximum and mean velocities, respectively, compared with those from PIV. The proposed material possesses the advantage of the single-phantom ability to improve the ultrasound flow phantom for validation of flow.

Visible Emission Line Spectroscopy of the Solar Corona During the 2019 Total Solar Eclipse

Spectroscopic measurements of the low solar corona are crucial to understanding the mechanisms that heat the corona and accelerate the solar wind, yet the lowest solar radii (R_{odot }) of the corona are difficult to observe. Our expedition collected narrow wavelengths of visible light at 530.3, 637.4, and 789.2 nm emitted by Fe xiv, x, and xi ions, respectively, from the total solar eclipse on 2019 July 2 at 20:40 UTC in Rodeo, Argentina with a bespoke 3-channel spectrometer. This paper describes the instrument and data calibration method that enables diagnostics out to {approx},1.0~R_{odot } above the solar limb within a bright helmet streamer. We find that Fe x and xi lines are dominant through 0.3~R_{odot }, with Fe xiv maintaining a stronger signal at higher elevations. Thermal line width broadening is consistent with 1.5 MK for the cooler Fe x, 2 MK for Fe xi, and 3 MK for the hotter Fe xiv line, which can be interpreted as differing density scale heights within isolated, isothermal flux tubes. The Doppler measurements correspond to bulk plasma motion ranging from −12 to +2.5 km s−1, with Fe xiv moving at nearly an assumed solid body rotation rate throughout 1.0~R_{odot }. After considering coronal rotation, these measurements are likely associated with plasma motion along the dominant longitudinal orientation of the magnetic field at the streamer base within 0.4~R_{odot }. These results show that high-resolution spectroscopy of visible light offers valuable diagnostics of the low corona, and lend insight into the interconnected loop complexity within helmet streamers.

Analysis of the vibration characteristics of pin-connected hammer rotor of straw rubbing filament machine

The finite element method and the 3D laser Doppler measurement technology were used to simulate and test the vibration characteristics of the pin-connected hammer rotor. This was done to determine the critical speeds of the pin-connected hammer rotor of the straw rubbing filament machine and avoid the resonance of the straw rubbing filament machine during operation. The frequencies and mode shapes of the rotor’s first six free modes were determined. The accuracy of the pin-connected hammer rotor finite element model is validated by comparing calculation and test values. On this basis, the prestressed modes of the pin-connected hammer rotor under actual working conditions are calculated. The effect of the hammer swing angles rotating around the pin shaft is investigated, and the critical speeds of the pin-connected hammer rotor are calculated. The results indicate that the rotor has the same mode shapes at 11 kinds of joint swing angles, and the maximum relative error for each order frequency is 0.88%. It can be seen that the hammer-pin swing angles have little effect on the vibrational frequencies and mode shapes of the hammer-pin articulated rotor. Compared to the free modes, the prestressed modes all have an additional torsional mode and consist of two-mode shapes of global and local; the global mode shapes are similar to the free ones except for an additional torsional mode shape, with increased amplitudes and modal frequencies; the local mode shapes mainly occur in cutting knives and hammers. The critical speed range of the rotor of the 9ZR-2.2 straw rubbing filament machine must be 2076.99–2348.32 r/min which is based on ensuring the processing quality of straw. The study provides a reference method for investigating the vibration characteristics of pin-connected hammer rotors. It is also of great practical importance to scientifically predict the critical speed of a pin-connected hammer rotor in order to reduce failure and safety accidents.

Development of a methodology for evaluating spaceborne W-band Doppler radar by combined use of Micro Rain Radar and a disdrometer in Antarctica

Ground-based snowfall observations over Antarctica are rare due to the harsh environment and high logistical, equipment maintenance, and operational costs. Satellite measurements are crucial to provide continent-wide precipitation estimates, and this highlights the importance of validating the satellite estimates with measurements collected by ground-based Antarctic stations. The NASA CloudSat satellite, launched in 2006, is equipped with a 94 GHz (W-band) Cloud Profiling Radar (CPR) that provides measurements of reflectivity profiles of clouds and precipitation, whereas the incoming ESA/JAXA EarthCARE mission will add Doppler capability to a 94 GHz radar. This study explores how the synergy between two instruments available at most Antarctic stations, i.e., Micro Rain Radar (24 GHz, K-band) and laser disdrometer, can be used to validate satellite-borne W-band radar measurements, including Doppler estimates. A new validation methodology (K2W) was proposed to combine these instruments for simulating the 94 GHz reflectivity and Doppler measurements from Micro Rain Radar spectra. Assessment of the proposed K2W conversion methodology showed that the CloudSat Ze profiles can be simulated by the method with 0.2 dB mean difference at the lowest satellite radar range bin when time lag within ±12.5 min and the distance within 25 km around the CloudSat overpass were considered. With the K2W method, the 94 GHz Doppler velocity below 1 km altitude that would be observed by EarthCARE was obtained, and the standard deviation of the simulated Doppler velocity was found to be smaller than about 0.2 m s−1. The simulated 94 GHz Doppler radar profile information, which is less affected by attenuation compared to ground-based 94 GHz radar, will significantly improve the quantification of precipitation over Antarctica. This methodology will be applied to further assess the EarthCARE CPR Doppler velocity measurement accuracy as well as the Level 2 standard products for precipitation in Antarctica and at many other ground observation sites.

Doppler Positioning of Dynamic Targets with Unknown LEO Satellite Signals

A new concept of global navigation based on Doppler measurements from a large low Earth orbit (LEO) constellation is investigated that has potential to serve as a complement or backup to global navigation satellite systems (GNSSs) to provide navigation and positioning services in GNSS denial environments. In this work, we investigate the potential of LEO communication satellite opportunity signals in dynamic navigation, establish LEO satellite Doppler positioning equations, derive the main error sources affecting the Doppler positioning results of a dynamic target, and analyze the impact of each error source on positioning accuracy through a simulation. The results show that the orbit error and clock drift had a large impact on positioning accuracy. This navigation scheme would be more competitive if it could provide high-precision satellite orbits and accurate Doppler measurements. The obtained results show that the LEO satellite signals used as navigation opportunity signals are an attractive alternative in GNSS rejection environments for high dynamic targets.

Doppler Ultrasound Flow Reversal in the Superior Sagittal Sinus to Detect Cerebral Venous Congestion in Vein of Galen Malformation.

Vein of Galen malformation is a rare congenital cerebrovascular malformation. In affected patients, increased cerebral venous pressure constitutes an important etiologic factor for the development of brain parenchymal damage. The aim of this study was to investigate the potential of serial cerebral venous Doppler measurements to detect and monitor increased cerebral venous pressure. This was a retrospective monocentric analysis of ultrasound examinations within the first 9 months of life in patients with vein of Galen malformation admitted at <28 days of life. Categorization of perfusion waveforms in the superficial cerebral sinus and veins into 6 patterns was based on antero- and retrograde flow components. We performed an analysis of flow profiles across time and correlation with disease severity, clinical interventions, and congestion damage on cerebral MR imaging. The study included 44 Doppler ultrasound examinations of the superior sagittal sinus and 36 examinations of the cortical veins from 7 patients. Doppler flow profiles before interventional therapy correlated with disease severity determined by the Bicêtre Neonatal Evaluation Score (Spearman ρ = -0.97, P = < .001). At this time, 4 of 7 patients (57.1%) showed a retrograde flow component in the superior sagittal sinus, whereas after embolization, none of the 6 treated patients presented with a retrograde flow component. Only patients with a high retrograde flow component (equal or more than one-third retrograde flow, n = 2) showed severe venous congestion damage on cerebral MR imaging. Flow profiles in the superficial cerebral sinus and veins appear to be a useful tool to noninvasively detect and monitor cerebral venous congestion in vein of Galen malformation.

Carotid Artery Corrected Flow Time Measured by Wearable Doppler Ultrasound Accurately Detects Changing Stroke Volume During the Passive Leg Raise in Ambulatory Volunteers.

The change in the corrected flow time of the common carotid artery (ccFTΔ) has been used as a surrogate of changing stroke volume (SVΔ) in the critically-ill. Thus, this relatively easy-to-obtain Doppler measure may help clinicians better define the intended effect of intravenous fluids. Yet the temporal evolution of SVΔ and ccFTΔ has not been reported in volunteers undergoing a passive leg raise (PLR). We recruited clinically-euvolemic, non-fasted, adult, volunteers in a local physiology lab to perform 2 PLR maneuvers, each separated by a 5 minute 'wash-out'. During each PLR, SV was measured by a non-invasive pulse contour analysis device. SV was temporally-synchronized with a wireless, wearable Doppler ultrasound worn over the common carotid artery that continuously measured ccFT. 36 PLR maneuvers were obtained across 19 ambulatory volunteers. 8856 carotid Doppler cardiac cycles were analyzed. The ccFT increased nearly ubiquitously during the PLR and within 40-60 seconds of PLR onset; the rise in SV from the pulse contour device was more gradual. SVΔ by +5% and +10% were both detected by a +7% ccFTΔ with sensitivities, specificities and areas under the receiver operator curve of 59%, 95% and 0.77 (p < 0.001) and 66%, 76% and 0.73 (p < 0.001), respectively. The ccFTΔ during the PLR in ambulatory volunteers was rapid and sustained. Within the limits of precision for detecting a clinically-significant rise in SV by a non-invasive pulse contour analysis device, simultaneously-acquired ccFT from a wireless, wearable ultrasound system was accurate at detecting 'preload responsiveness'.

Retraction.

Maged, A.M., ElNassery, N., Fouad, M., Abdelhafiz, A. and Al Mostafa, W. (2015), Third-trimester uterine artery Doppler measurement and maternal postpartum outcome among patients with severe pre-eclampsia. International Journal of Gynecology & Obstetrics, 131: 49-53. https://doi.org/10.1016/j.ijgo.2015.03.045. The above article, published online on 18 June 2015 on Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal's Editor-in-Chief, Professor Michael Geary, the International Federation of Gynecology and Obstetrics, and John Wiley & Sons Ltd. The journal's Editor-in-Chief was contacted by a third party who raised concerns about the article. During review of the study data by the Editorial Board, it was found that Figures 1, 2 and 3 contained statistical analysis errors that were too substantial to correct using an Erratum, and that these errors would likely impact the reported clinical outcomes. There were also inconsistencies in the numbers presented within the tables, between the tables, and with the individual patient data. As a result, the journal no longer has confidence in the results and conclusions drawn and is issuing this retraction.

P154 HUMAN CORONARY INFLAMMATION AT CORONARY COMPUTED TOMOGRAPHY IN PATIENTS WITH INOCA

Abstract Background A new imaging metric using coronary computed tomography angiography (CCTA), addressing the peri–coronary adipose tissue (PCAT) computed tomography (CT) attenuation, has been clinically validated. This method provides information regarding coronary inflammation. It is unclear how coronary inflammation affects microvascular function. The non–invasive evaluation of coronary flowvelocity reserve is widely used in clinical practice using Doppler measurement on the left anterior descending coronary artery (CFVR–lad) during stress–echocardiography (SE).We hypothesize that coronary inflammation affects CFVR–lad and, in the absence of overt CAD, they are significantly correlated. Methods We evaluated the relationship between coronary inflammation (by PCAT CT attenuation) and coronary microvascular function (by CFVR–lad) in subjects with no or non–obstructive (diameter stenosis &amp;lt;70%) coronary artery disease (CAD). Results Two–hundred and two subjects were enrolled in the study. The relationship between PCAT CT attenuation and CFVR–lad show a significant inverse relationship in the entire group of subjects enrolled in the study (r = −0.32, p &amp;lt; 0.001). Correlation between PCAT CT attenuation and CFVR–lad was significant in subjects with no or mild CAD–lad, while this was not the case in subjects with intermediate CAD–lad. The R and R2 were respectively −0.40, −0.16 in subjects without CAD (p &amp;lt; 0.001) and − 0.35 and − 0.12 in subjects with mild CAD–lad (p = 0.001). Conclusions The main finding of the current study is the independent relationship between coronarymicrovascular function, by Doppler CFVR–lad during SE, in subjectswithout severely obstructive CAD in the left anterior descending coronary artery, and the level of local coronary inflammation, by PCAT attenuation measurement on CCTA.

Fetal epicardial fat thickness in non-severe idiopathic polyhydramnios: Its impact on fetal cardiac function and perinatal outcomes.

This study aimed to evaluate fetal epicardial fat thickness (EFT) along with fetal myocardial performance index (MPI) and its effects on perinatal outcomes in non-severe idiopathic polyhydramnios (IP). This prospective study included 92 participants, 32 diagnosed with non-severe IP, and 60 healthy pregnant women. Amniotic fluid indices (AFI), umbilical and middle cerebral artery Doppler, EFT, and MPI measurements were performed for all patients. The fetal EFT and MPI values were statistically higher in the non-severe IP group than in the control group (p = 0.0001, p = 0.014, respectively). The optimal fetal EFT cutoff value for predicting non-severe IP disease was found as 1.3 mm with a specificity of 81.7% and sensitivity of 59.4%. The EFT cutoff for predicting cesarean section in non-severe IP cases was 1.25 mm (p = 0.038). Apgar scores, neonatal intensive care unit, respiratory distress syndrome, and stillbirth rates were not different between groups. In this study, EFT and MPI were found to be higher in non-severe IP cases compared to controls. It was observed that the increase in MPI and EFT was associated with the increase in cesarean rates, but not with adverse fetal outcomes.