Pulsed Doppler Research Articles

Evaluation of cerebral autoregulation in dogs via transcranial color-coded duplex sonography and transient hyperemia testing.

To evaluate the changes in flow velocities of the middle cerebral artery before and after a carotid compression maneuver using transcranial color-coded duplex sonography (TCCD) in healthy anesthetized dogs under mechanical ventilation. Prospective study. University teaching hospital. Eleven healthy adult dogs. A 5-second carotid occlusion maneuver was performed to evaluate cerebral autoregulation (CA). After 10minutes of stable anesthesia, the middle cerebral artery was evaluated by TCCD. Dogs were positioned in sternal recumbency with the head raised to the level of the phlebostatic axis. The systolic peak velocity (Vp) was measured using pulsed Doppler mode. CA was evaluated through the transient hyperemia test (THT), which assesses changes in the Vp after a 5-second transient compression of the ipsilateral common carotid artery and is expressed as the ratio between the Vp flow before and after carotid compression. The Vp before and after carotid occlusion was compared using the Wilcoxon signed-rank test. The median Vp of the middle cerebral artery after the carotid compression maneuver was significantly higher than the median Vp before compression (median [interquartile range, IQR]: 47.7cm/s [34.3]vs64.1cm/s [24.4]; P=0.003). The median THT obtained was 1.20 (IQR: 0.37). The current study demonstrated a significant increase in the Vp of the middle cerebral artery after a 5-second temporary occlusion of the ipsilateral carotid artery in healthy anesthetized dogs under mechanical ventilation. These findings suggest that the noninvasive TCCD methodology could be valuable for assessing CA in dogs. Additional studies using this technique in neurocritical animals are required to confirm its usefulness.

Echocardiographic Evaluation of Chronic Aortic Regurgitation: Comparison With Cardiac Magnetic Resonance and Implications for Guideline Recommendations.

Guidelines for echocardiographic evaluation of aortic regurgitation (AR) have not been validated against an independent quantitative standard. The aim of this study was to evaluate the accuracy of the ASE (American Society of Echocardiography) AR guidelines against cardiac magnetic resonance (CMR) and to develop simplified approaches for detection of significant AR. Patients with AR underwent echocardiography and CMR<4 hours apart. AR severity was graded according to ASE guidelines. Quantitation of regurgitant volume (RegV) was performed with pulsed Doppler at the mitral annulus and right ventricular outflow compared with left ventricular (LV) outflow, and with proximal isovelocity surface area. The authors studied 81 patients; median age was 52 years, and 58% had a bicuspid aortic valve. According to echo, 35 (43%) patients had mild AR, 18 (22%) moderate, 12 (15%) moderate to severe, and 16 (20%) had severe AR. The area under the curve (AUC) for detection of severe AR by CMR using ASE grading was 0.9 (82.4% sensitivity and 96.9% specificity). Feasibility of RegV quantitation was >88% using either echo volumetric method, and it was low for proximal isovelocity surface area (37%). The highest accuracy for echo parameters against CMR was seen with vena contracta width, jet width, and LV end-diastolic volume index (AUC: 0.86-0.89); pressure half-time had the lowest accuracy. Without RegV quantitation, a vena contracta width≥0.5cm and indexed LV end-diastolic volume≥82mL/m2 had 95.5% positive predictive value and 87.5% negative predictive value for identifying≥moderate to severe AR by CMR (AUC: 0.89). The ASE guidelines display very good performance in identifying significant AR. A simplified approach using vena contracta width and LV volumes can be used to reliably identify significant AR. Further validation of the findings in larger cohorts and against clinical outcomes is needed.

Comprehensive echocardiographic and biomarker assessment of patients with diabetic ketoacidosis

BackgroundSystemic stress, inflammation, and hydroelectrolytic and acid‒base abnormalities observed during diabetic ketoacidosis (DKA) can cause changes in the heart and even induce cardiovascular damage. We aimed to evaluate the structure and function of the heart during and after a DKA episode via echocardiography and biomarker assessment.MethodsWe performed a transthoracic echocardiogram (TTE) in subjects with an episode of DKA in the first 4–6 h of treatment. We evaluated left ventricular wall thickness, diameters and volumes, as well as systolic and diastolic function using tissue Doppler imaging, pulsed wave Doppler and left ventricular ejection fraction (LVEF). Left ventricular function was also assessed with global longitudinal strain (GLS). We obtained cardiac troponin levels in the first 24 h after admission. A second TTE was performed following the same protocol 6–12 h after the resolution of the DKA episode.ResultsWe included a total of 20 subjects. The mean age was 33 ± 13.6 years; 70% were female, and 70% had type 1 DM. 75% of the patients experienced severe episodes, and the rest experienced moderate episodes. Left ventricular isovolumetric contraction and ejection time were significantly shorter during DKA and prolonged after the resolution of the episodes (47.6 ± 9.9 vs. 62.2 ± 14.1, p = < 0.001) and (218.6 ± 37.9 vs. 265.06 ± 34.7). The isovolumetric relaxation time was also shorter during DKA, (41.72 ± 8.29 vs. 59.32 ± 17.98, p = < 0.001). Volumes and diameters of the left ventricle increased significantly after DKA resolution. We found no difference between LVEF or GLS during and after DKA resolution. 20% of the participants had troponin elevations, half of whom had moderate episodes and half of whom had severe episodes. 35% had LV dysfunction, 28.5% both in GLS and LVEF. 28.5% occurred after DKA resolution, with alterations in GLS.ConclusionsDiabetic ketoacidosis induces changes in the structure and function of the heart, which are mostly transient, reflect the presence of a hyperdynamic state and resolve after the resolution of the episode. Some subjects present with evidence of myocardial injury with elevated cardiac troponin and left ventricular dysfunction.Graphical abstractIcons in the graphical abstract are made by Freepik from www.flaticon.com.

Percutaneous decannulation of extracorporeal membrane oxygenation using MANTA device: A real-world single-center experience.

The MANTA vascular closure device (VCD) represents a novel approach to achieving hemostasis after large-bore femoral access procedures. Numerous clinical studies have evaluated the efficacy of the MANTA device across a range of patient populations undergoing different procedures. However, there is still a paucity of data available concerning the use of MANTA devices in aiding the decannulation of venoarterial extracorporeal membrane oxygenation (VA-ECMO). To present our single-center experience of utilizing the MANTA VCD in patients undergoing this procedure. This single-center study included all patients undergoing percutaneous decannulation of femoral VA-ECMO using the MANTA plug-based VCD between January 2021 and October 2023 at University Hospitals Cleveland Medical Center. Inclusion criteria were adult patients who required prolonged (> 24 hours) hemodynamic support with VA-ECMO. Outcomes included all-cause mortality, hemostasis, bleeding, limb ischemia, and site infection. This is a retrospective cohort study of 19 patients with a mean age of 56.8 years. Twelve of them were males with a mean body mass index of 29. The most common extracorporeal membrane oxygenation indication was acute coronary syndrome complicated by cardiogenic shock at 36.8%. The mean length of intensive care unit stay for these patients was 18.8 ± 8.42 days. Seventeen out of 19 patients survived to discharge. The MANTA device was successfully deployed in 19 patients, with 10 procedures conducted at the bedside and 9 in an operating room setting. Complete hemostasis was achieved within 5 minutes of MANTA deployment in 17 out of 19 patients. In 2 patients manual compression after Manta deployment was required to achieve adequate hemostasis. Additionally, acute lower extremity ischemia was noted in two patients, necessitating endovascular interventions. No infections were reported at the site of MANTA deployment. Overall, based on our experience and that of other centers, the MANTA VCD has proven to be a simple, safe, and effective percutaneous technique for facilitating in the OR, but most of all it opens the opportunity for bedside VA-ECMO decannulation. Post-decannulation ischemic complications are higher in this series of sick patients when compared with elective procedures like transcatheter aortic valve replacement and endovascular aneurysm repair. Additionally, operators should be mindful of the incidence of ischemic complications. Distal Doppler pulse signals should always be checked, to indicate bailout options when this occurs.

Time Interval Between Right Ventricular Early Diastolic Velocity by Tissue and Pulse Wave Doppler: An Index of Right Atrial Pressure in Pulmonary Hypertension Patients.

Background: A reversal of time difference between the onset of early diastolic velocity (e') during tissue Doppler imaging and the onset of mitral inflow (E) has been observed in cases of elevated left atrial pressure. Whether this interval (Te'-E) may be useful to assess right atrial pressure has never been investigated, neither in healthy subjects nor in pulmonary hypertension patients. Methods: Right ventricular Te'-E was assessed in patients with pre-capillary pulmonary hypertension and compared with healthy volunteers who underwent comprehensive echocardiography examination. Te'-E is the difference between the interval from R wave at the superimposed electrocardiogram to the e' wave during right ventricular tissue Doppler imaging and the interval from the R wave to transtricuspid E wave during pulsed wave Doppler imaging. Right atrial pressure was invasively measured in pulmonary hypertension patients. Results: Fifty-six patients were enrolled. Te'-E was prolonged in pulmonary hypertension subjects compared with healthy subjects (p < 0.001). Amongst the pulmonary hypertension patients, strong correlations were found between Te'-E and right atrial pressure (r = -0.885, p < 0.001), systolic pulmonary pressure (r = -0.85, p < 0.001) and the duration of tricuspid regurgitation (r = 0.72, p < 0.001). The area under the receiver operating characteristic curve of Te'-E in identifying right atrial pressure higher than 15 mm of mercury was 0.992 (sensitivity 100%, specificity 83%). Conclusions: In contrast to the left ventricle, there is a delay in the proto-diastolic filling in pulmonary hypertension patients, which correlates with the increase in systolic pulmonary arterial pressure, right atrial pressure, tricuspid regurgitation duration and restrictive diastolic pattern.

The mitral to aortic/pulmonary velocity-time integral ratio is a simple, feasible and accurate discriminator for echocardiographic evaluation of severe isolated mitral regurgitation.

Echocardiographic quantification of mitral regurgitation (MR) remains challenging, requiring dedicated image acquisition, and is limited by potential error from geometric assumptions of annular dimensions. Volume is a product of area and flow and assuming proportional mitral/aortic areas, an increased mitral-inflow volume compared to LV/RV-outflow semi-quantitatively represents greater MR regurgitant volume. Therefore, we investigated the feasibility and diagnostic performance of the mitral-aortic velocity-time integral(VTI) ratio in isolated MR. We also investigated the use of the mitral-pulmonary VTI ratio as an alternative in clinical situations where the LV outflow tract(LVOT) VTI could not be used. We reviewed 166 consecutive patients (33%, n = 54 severe MR by multi-parameter integrated expert opinion). Pulsed wave Doppler VTI at the mitral leaflet tips and the left ventricular outflow and continuous-wave Doppler of the RV outflow tract were measured individually and independently by blinded readers(expert and trainee status) to derive the ratio. Receiver operator characteristic area under the curve(AUC) comparison was calculated and compared with effective regurgitant orifice area(EROA > 40mm), regurgitant volume(RVol > 60mL), vena contracta(VC > 0.7cm), E-velocity > 1.2cm, systolic flow reversal(SFR), left atrial and ventricular dilatation. Increasing ratio was associated with severe MR(AUC 0.94) with optimal threshold defined at 1.3. This provided significant discrimination for severe MR(AUC 0.81) compared to EROA(0.68), VC(0.52), LV dilatation(0.69), LA dilatation(0.70), SFR(0.73), E-velocity(0.68) all p < 0.05, with sensitivity 82% and specificity 94%. The mitral-pulmonary VTI ratio demonstrated similar discrimination(AUC 0.92) with optimal threshold defined at 1.14. Excellent inter-observer reproducibility(intra-class correlation 0.97) was seen between trainee and expert readers. There was no difference in AUC comparison by MR mechanism or patient rhythm. The mitral-aortic and mitral-pulmonary VTI ratios are simple, geometric-free parameters feasibly reproducible from routine echocardiographic datasets and are excellent discriminative tools for severe MR. Readers should consider integration of this parameter in routine reporting.

Using lightweight denoising network to suppress multiple barrage jamming in range‐Doppler domain

AbstractBarrage jamming technology poses a significant threat to radar detection functions, yet there is limited research on anti‐multiple barrage jamming using single‐channel radar systems. Addressing this gap, this paper proposes a framework for anti‐multiple barrage jamming based on range‐Doppler domain denoising. This framework first performs pulse compression and Doppler processing on the echo signal to enhance the signal‐to‐jamming ratio. The range‐Doppler spectrum data is then input into a deep denoising network to suppress multiple types of jamming. Additionally, the paper proposes a lightweight deep denoising network comprising a feature extraction module, a jamming suppression module, and a feature fusion module. The feature extraction module preliminarily extracts jamming features using multiple layers of depth‐wise and point‐wise convolution. The jamming suppression module removes noise at various resolutions through a lightweight encoding and decoding structure, effectively suppressing the barrage jamming signal. The feature fusion module uses convolution kernels with different sizes to merge the multiple features output by the jamming suppression module. Simulation results demonstrate that the proposed method effectively suppresses ten types of barrage jamming. Furthermore, a measured dataset is constructed to verify the method’s effectiveness.

Mesenteric blood flow and muscle sympathetic nerve activity during vasovagal syncope.

Vasovagal syncope is thought to be mediated by a progressive fall in cardiac output secondary to venous pooling of blood in the splanchnic circulation. How and when this occurs before syncope has not been determined. A total of 20 patients who became hypotensive during head-up tilt (age 40.9 ± 3.4 years; 10 females) were divided into two groups-the glyceryl trinitrate (GTN) group (n = 12) and the vasovagal syncope (VVS) group (n = 8) - on the basis of whether or not nitroglycerine provocation was required. They were compared with a control group (age 38.6 ± 3.3; 8 females; n = 13). Hemodynamics, including superior mesenteric artery blood flow (SMABF) and muscle sympathetic nerve activity (MSNA) were recorded continuously during early tilt, presyncope and recovery. We used pixel-weighting to calculate average velocity from the pulsed Doppler velocity envelope. During baseline and early tilt, resistance to mesenteric blood flow was lower in the VVS group: 0.30 ± 0.02 to 0.30 ± 0.02mmHg/ml/min versus controls 0.30 ± 0.03 to 0.38 ± 0.04mmHg/ml/min (p = 0.05). During presyncope, as blood pressure and stroke volume gradually fell, SMABF was higher in the VVS group, falling from 370 ± 46 to 248 ± 35ml/min, versus controls, falling from 342 ± 51 to 233 ± 19 (p = 0.03). At this time, MSNA was lower in the VVS group than controls: 39 ± 4 to 34 ± 3 bursts/min versus 45 ± 2 to 48 ± 3 (p = 0.001). During presyncope, increased splanchnic blood flow may pool more blood in capacitance vessels resulting in decreased venous return and cardiac output. This may be secondary to decreased vasoconstrictor sympathetic activity.

Design of compact signal source with reduced phase noise for airborne pulse Doppler RF sensor

Abstract In this article, a low phase noise signal source to be used as local oscillator in pulse Doppler radio frequency (PDRF) sensor is proposed. Innovative design techniques for realization of the low phase noise frequency source using phase-locked loop (PLL) and dielectric resonator (DR) are presented. Qualitative investigations have been carried out on the effect of phase noise in PDRF sensor performance. An X-band vibration resistant PLL-based frequency source with phase noise better than −95 dBc at 1 kHz frequency offset has been designed here. It also presents the design of a 7.6 GHz low phase noise, vibration resistant DR oscillator. Systematic analysis of the key design aspects, their thermal-vibrational stability, and ease of integration with hybrid microwave integrated circuits have been disclosed. A prototype board is fabricated, assembled in a compact mechanical enclosure of dimension 55 × 55 × 15 mm3. Finally, developed module is experimentally validated under 7.6 g rms magnitude random vibration test in three axes and compared results with other state of-the-art similar works. The comparison clearly shows the merit of present research work over other similar existing works.

Evaluation of lateral sagittal infraclavicular block according to inferior vena cava collapsibility index (VCI-CI): An observational study.

Depending on the total amount of fluid, changes occur in the amount of fluid in the peripheral area. The aim of this study was to observe the differences caused by hemodynamic changes after lateral sagittal infraclavicular block (LS-ICB) according to the inferior vena cava collapsibility index (VCI-CI). In this prospective, observational study (Clinical Trial Number: NCT05968105), patients undergoing elective hand and wrist surgery with LS-ICB were classified according to VCI-CI, with Group 1 defined as inferior vena cava (VCI) diameter < 1.5 cm and VCI-CI > 50% and Group 2 defined as VCI diameter > 1.5 cm and VCI-CI < 50%. Groups were compared for demographic characteristics, defined durations, rescue analgesics, and complications. Continuous hemodynamic parameters and pulsed wave Doppler were evaluated within groups. Demographic characteristics and time periods were comparable between the groups. Hemodynamic parameters and pulsed wave Doppler measurements showed no significant differences. However, while Group 1 remained consistent, Group 2 exhibited differences in axillary artery diastolic diameter and axillary artery contractility index. A significant statistical difference was observed in Group 1 for the perfusion index at 30 minutes and postoperatively, whereas Group 2 remained consistent. The dosage and number of patients requiring rescue analgesics were similar across both groups, and no complications were reported. Blood flow increased after LS-ICB without a corresponding increase in axillary artery diameter. Group 1 showed a tendency toward a lower perfusion index in the postoperative period.

Comparative Approach to Performance Estimation of Pulsed Wave Doppler Equipment Based on Kiviat Diagram

Quality assessment of ultrasound medical systems is a demanding task due to the high number of parameters to quantify their performance: in the present study, a Kiviat diagram-based integrated approach was proposed to effectively combine the contribution of some experimental parameters and quantify the overall performance of pulsed wave Doppler (PWD) systems for clinical applications. Four test parameters were defined and assessed through custom-written measurement methods based on image analysis, implemented in the MATLAB environment, and applied to spectral images of a flow phantom, i.e., average maximum velocity sensitivity (AMVS), velocity measurements accuracy (VeMeA), lowest detectable signal (LDS), and the velocity profile discrepancy index (VPDI). The parameters above were scaled in a standard range to represent the four vertices of a Kiviat plot, whose area was considered the overall quality index of the ultrasound system in PWD mode. Five brand-new ultrasound diagnostic systems, equipped with linear array probes, were tested in two different working conditions using a commercial flow phantom as a reference. The promising results confirm the robustness of AMVS, VeMeA, and LDS parameters while suggesting further investigations on the VPDI.

Eye microcirculation in glaucoma. Part 1. Diagnostic methods

Glaucoma is a socially significant disease, which is a wide group of polyetiological diseases. In the etiology of primary glaucoma, in addition to the mechanical theory, a vascular mechanism is also distinguished, and therefore, the search and development of the most informative and accurate method for studying ocular blood flow continues. Existing methods are divided into invasive and non-invasive. Invasive methods include angiography with intravenous fluorescein and indocyanine. Non-invasive methods include ultrasound Doppler mapping and pulsed Doppler modes, optical coherence tomography with angiography and laser speckle flowography. The review presents data on modern methods for ocular hemodynamics in glaucoma and ocular hypertension with technologies for studying retrobulbar blood flow and intraocular hemocirculation.

Quantification and assessment of the atmospheric boundary layer height measured during the AWAKEN experiment by a scanning LiDAR

The atmospheric boundary layer (ABL) height plays a key role in many atmospheric processes as one of the dominant flow length scales. However, a systematic quantification of the ABL height over the entire range of scales (i.e., with periods ranging from one minute to one year) is still lacking in literature. In this work, the ABL height is quantified based on high-resolution measurements collected by a scanning pulsed Doppler LiDAR during the recent American WAKE experimeNt (AWAKEN) campaign. The high availability of ABL height estimates (≈2200 collected over one year and each of them based on 10-min averaged statistics) allows to robustly assess five different ABL height models, i.e., one for convective thermal conditions and four for stable conditions. Thermal condition is quantified by a stability parameter spanning three orders of magnitude and probed by near-ground 3D sonic anemometry. The free-atmosphere stability, quantified by the Brunt–Väisälä frequency, is both calculated from simultaneous radiosonde measurements and obtained from the best fit of two of the chosen ABL height models. Good agreement is found between the data and three of the chosen models, quantified by mean absolute errors on the ABL height between 281 and 585 m. Furthermore, the seasonal variability of the convective ABL height model parameters (−15% to +23% with respect to the year baseline) agrees with the variability of buoyancy-generated turbulence caused by the variation in solar radiation throughout the year.

Subclinical left ventricular structural and functional alterations in children with obesity: is body mass or insulin resistance the main issue?

Obesity is an independent risk factor for cardiovascular diseases. The study aims to assess the left ventricular structure and functions in children with obesity. This study included 29 patients with metabolic syndrome, 31 patients with obesity without metabolic syndrome, and 30 healthy children of similar age and gender. Demographic, anthropometric, and biochemical findings and left ventricular structure and functions evaluated by conventional pulsed wave Doppler and tissue Doppler echocardiography were compared. The left ventricular mass index and relative wall thickness were significantly higher in children with obesity compared to controls. The mean left ventricular mass index of children with metabolic syndrome was also higher than for those without it. Most children with obesity had normal left ventricular geometry; concentric hypertrophy (27.6%) was more common in children with metabolic syndrome, and eccentric hypertrophy (25.7%) was more common in those without. The early to late diastolic mitral annular velocity ratios obtained with conventional pulsed wave Doppler echocardiography and tissue Doppler echocardiography (E/A and Em/Am, respectively) were lower in children with obesity than controls. In addition, the ratio obtained by tissue Doppler echocardiography was lower in children with metabolic syndrome than without. The homeostatic model assessment of insulin resistance, systolic blood pressure, and body mass index has been identified as independent factors for left ventricular structures and functions. Obesity causes subclinical left ventricular hypertrophy and diastolic dysfunction. Additional metabolic syndrome-related risks lead to further deterioration of cardiac morphology and functions.

Ultrasonographic assessment of the fetal heart in intrahepatic cholestasis of pregnancy: Pulsed wave Doppler, M-mode, and tissue Doppler imaging prospective study.

To investigate the fetal heart using pulsed wave Doppler, M-mode, and tissue Doppler imaging (TDI) in cases of intrahepatic cholestasis of pregnancy (ICP). This prospective study was conducted at a single tertiary center and included 35 patients with ICP and 70 healthy pregnant women at 28-36 weeks of pregnancy. Among the patients with ICP, 26 had serum bile acid (SBA) levels less than 40 μmol/L and nine had SBA levels of 40 μmol/L or greater. Pulsed wave Doppler, M-mode, and TDI evaluations were performed on the patients to assess fetal cardiac function. The ICP group exhibited significantly higher myocardial performance index (MPI) and isovolumetric relaxation time (IRT), but similar isovolumetric contraction time (ICT). The tricuspid and mitral valve E, A, and E/A ratios were significantly reduced in the ICP group. The TDI parameters showed significantly reduced tricuspid and mitral valve E'/A' ratios in the ICP group compared with the control group (P < 0.001). The E/E' ratio was significantly increased in the ICP group (P < 0.001). According to the M-mode Doppler findings, tricuspid and mitral annular plane systolic excursion values were significantly decreased in the ICP group (P = 0.005 and P = 0.001, respectively). In the subgroup analysis, MPI and IRT were significantly higher in the severe ICP group. ICP might induce changes in the fetal heart during the early systolic and diastolic phases. The detection of these early changes using M-mode and TDI during the antenatal period can provide valuable insights into the condition of the fetus.

Left atrial appendage emptying velocity and left ventricular function as predictors of inotropic support in patients undergoing elective off-pump coronary artery bypass grafting

Abstract Background: Patients undergoing elective off-pump coronary artery bypass grafting (CABG) are at risk of hemodynamic instability, ischemia, arrhythmia, and dysfunction. These events need to be managed by pharmacological supports or relieving of mechanical obstruction (octopus) of the heart to maintain the hemodynamic stability. There is a paucity of data on the effect of left ventricular (LV) dysfunction on left atrial appendage (LAA) emptying velocity. We evaluated the relationship between LV function and LAA emptying velocity and requirement of inotropic support perioperatively. Materials and Methods: In this prospective open-label all-comer study, fifty patients undergoing elective off-pump CABG under general anesthesia, we measured LAA emptying velocity by pulsed wave Doppler and evaluated if it could predict the need for inotropes perioperatively. It is a case series of 50 patients without a comparator arm. We measured pulsed wave Doppler across the mitral valve leaflet and early mitral inflow velocity (Evel) and late mitral inflow velocity, tissue Doppler at the lateral annulus of the mitral valve (e’) and also calculated the ratio of Evel and e’. Need for inotrope in the intraoperative and postoperative period was captured perioperatively. Vasoactive-inotropic score (VIS) was calculated for all the patients. Results: The VIS was significant (P &lt; 0.0001, with odds ratio of 131.6 and confidence interval of 95% (0.9–1). However, there was no significant correlation between ejection fraction (EF) and VIS (P = 0.87). In patients with the need of inotropes, LAA emptying velocity was significantly increased in the postgrafting period as compared to the pregrafting period (75.64 cm/s vs. 57.9 cm/s, P &lt; 0.001). Conclusion: The assessment of LAA emptying velocity value was a useful predictor of the need of inotropic support during off-pump surgery, especially during Obtuse marginal and Ramus grafting. This study paves the need of larger case–control studies to validate the findings.

Microwave local oscillator signal generation with low near-carrier phase noise based on cascaded optoelectronic oscillators

A new scheme to generate microwave local oscillator (LO) signals with low near-carrier phase noise is proposed based on cascaded optoelectronic oscillators (OEOs). In the proposed scheme, an active mode-locking OEO is utilized to generate a microwave comb with low near-carrier phase noise. Through injecting the generated microwave comb into another OEO with a well-designed loop delay, microwave LO signals with low near-carrier phase noise can be generated. The feasibility of the scheme is numerically and experimentally demonstrated. In the experiment, a microwave LO signal at 10.0005 GHz is generated with a spurious suppression ratio of 25 dB and a near-carrier phase noise of −91 dBc/Hz@100 Hz. Compared with the microwave LO signal directly generated by using the OEO without injection, the near-carrier phase noise is reduced by 23 dB. The proposed scheme can thus be used to enhance the sensitivity of the pulse Doppler radar system for detecting small targets with low altitude and slow speed.

E/e' Ratio as a Predictor of In-Hospital Complications and Clinical Outcomes of Acute Myocardial Infarction.

Introduction Acute myocardial infarction (AMI) is the leading cause of death worldwide. E/e' ratio can predict complications and mortality in the long term, but information on its effectiveness in in-hospital settings is limited. Identifying high-risk patients effectively is crucial for early management, which may improve overall clinical outcomes. This study evaluated the predictive value of the E/e' ratio of in-hospital complications and clinical outcomes of AMI. Methods Patients presenting with AMI to Batumi Referral Hospital, Georgia, between December 2023 and May 2024, were examined in this study. During the first 24 hours of hospitalization, all patients underwent two-dimensional echocardiograms. Early diastolic filling velocity (E) was measured by pulsed wave Doppler, and early mitral annulus velocity (e') was measured by tissue Doppler. Based on the ratio of the two measures, patients were divided into three groups: E/e'<8, E/e' 8-14, and E/e'>14. Results A total of 113 patients (92 males and 21 females) were included in the study. The average age of the patients was 62 years (SD = 11.71). Overall, 27 (23.8%) patients were diagnosed with ST-elevation myocardial infarction (STEMI) and 86 (76.2%) patients with non-ST-elevation myocardial infarction (NSTEMI). The E/e' ratio was normal (less than 8) in 39 (34.5%) patients (group A), increased to 8-14 in 46 (40.7%) (group B), and greater than 14 in 28 (24.8%) (group C). The percentage of deaths in group B was higher than that in group A (2.2% vs 0%), and in group C, it was significantly higher than that in group B (17.9% vs 2.2%) (p<0.05). The percentage of heart failure developed during hospitalization was higher in group B compared to group A (54.3% vs 2.6%), and it was significantly higher in group C compared to group B (67.9% vs 54.3%) (p<0.05). The percentage of arrhythmias developed during hospitalization was higher in group B compared to group A (13.0% VS 2.6%), and in group C, was significantly higher compared to group B (35.7% VS 13.0%) (p<0.05). The percentage of cardiogenic shock in group B was higher than that in group A (4.3% VS 0%), and in group C, it was significantly higher than group B (25.0% VS 4.3%) (p<0.05). No significant association was found between E/e' ratio and recurrent angina, nor was there a significant association between all-cause deterioration during hospitalization (p>0.05). Conclusions Both slightly and significantly elevated E/e' ratios are predictors of in-hospital complications and may be used to identify individuals at high risk of negative health outcomes.

Review of speckle tracking analysis to measure the size, shape, and contractility of the fetal heart in fetuses with congenital heart defects.

Evaluation of the fetal heart involves two approaches. The first describes a screening protocol in which the heart is imaged in transverse planes that includes the four-chamber view (4CV), left and right outflow tracts, and the 3-vessel-tracheal view. The second approach is a fetal echocardiogram that requires additional cardiac images as well as evaluating ventricular function using diagnostic tools such as M-mode and pulsed Doppler ultrasound. Speckle tracking analysis of the ventricular and atrial endocardium of the fetal heart has focused primarily on computing longitudinal global strain. However, the technology enabling this measurement to occur has recently been adapted to enable the clinician to obtain numerous additional measurements of the size, shape, and contractility of the ventricles and atrial chambers. By using the increased number of measurements derived from speckle tracking analysis, we have reported the ability to screen for tetralogy of Fallot, D-transposition of the great arteries (D-TGA), and coarctation of the aorta by only imaging the 4CV. In addition, we have found that measurements derived from speckle tracking analysis of the ventricular and atrial chambers can be used to compute the risk for emergent neonatal balloon atrial septostomy in fetuses with D-TGA. The purpose of this review is to consolidate our experience in one source to provide perspective on the benefits of speckle tracking analysis to measure the size, shape, and contractility of the ventricles and atria imaged in the 4CV in fetuses with congenital heart defects.

The Cardiac Pulsed Wave Doppler Pattern of the Common Femoral Vein in Diagnosing the Likelihood of Severe Pulmonary Hypertension: Results from a Prospective Multicentric Study.

Background and Objectives: Pulmonary hypertension (PH) is a clinical condition with high mortality rates, particularly in patients over 65. Current guidelines recommend assessing the likelihood of pulmonary hypertension (LPH) using advanced echocardiography before proceeding to right heart catheterization. This study proposed using the common femoral vein (CFV), an accessible vein that reflects right atrial pressure, as an alternative method to assess the high likelihood of pulmonary hypertension (H-LPH). Materials and Methods: This prospective observational study included 175 emergency patients from three hospitals. Ultrasound assessed the pulsed wave Doppler (PW-Doppler) morphology of the CFV. This diagnostic yield for H-LPH was evaluated alongside traditional ultrasound parameters (right-to-left ventricular basal diameter ratio greater than 1 (RV > LV), septal flattening, right ventricular outflow acceleration time (RVOT) of less than 105 ms and/or mesosystolic notching, pulmonary artery diameter greater than the aortic root (AR) diameter or over 25 mm, early pulmonary regurgitation maximum velocity > 2.2 m/s; TAPSE/PASP less than 0.55, inferior vena cava (IVC) diameter over 21 mm with decreased inspiratory collapse, and right atrial (RA) area over 18 cm2). Results: The CFV's PW-Doppler cardiac pattern correlated strongly with H-LPH, showing a sensitivity (Sn) of 72% and a specificity (Sp) of 96%. RA dilation and TAPSE/PASP < 0.55 also played significant diagnostic roles. Conclusions: The CFV's PW-Doppler cardiac pattern is an effective indicator of H-LPH, allowing reliable exclusion of this condition when absent. This approach could simplify initial LPH evaluation in emergency settings or where echocardiographic resources are limited.