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Objective: To evaluate the efficacy of erector spinae plane block (ESPB) on intraoperative hemodynamic stability, opioid and inhalation anesthetic requirements and postoperative analgesic effects in patients undergoing surgical stabilization of rib fractures (SSRFs)., Methods: We retrospectively reviewed 173 patients who underwent surgical stabilization of rib fractures between May 2020 and December 2023. The patients were allocated into the ESPB group or the control group. Demographic data, intraoperative hemodynamic parameters, total intraoperative opioid consumption, the average minimum alveolar concentration (MAC) of inhalational anesthetics, postoperative simple analgesics and opioid consumption and the length of hospital stay were included in the analysis., Results: Compared with the control group, the ESPB group had a lower heart rate (HR) in the first 90 min after surgical incision and lower systolic blood pressure (SBP) and mean arterial pressure (MAP) at the beginning of surgery. Intraoperatively, a notable reduction in fentanyl consumption was observed in the ESPB group (p = 0.004), whereas no significant difference was observed in the average MAC of inhalational agents (p = 0.073). Postoperatively, the ESPB group required fewer doses of simple analgesics in the first 24 h (p < 0.001) and 48 h (p = 0.029). No statistically significant difference in the length of hospital stay (p = 0.608) was observed between the groups., Conclusion: ESPB was shown to enhance intraoperative hemodynamic stability, reduce opioid consumption and decrease postoperative analgesic consumption in patients who underwent SSRF. These results suggest that ESPB may serve as a valuable component of multimodal analgesia protocols for SSRF. Larger prospective studies are warranted to confirm the results and evaluate long-term outcomes., Competing Interests: Declarations Ethics approval and consent to participate The study was approved by the Institutional Review Board of Chang Gung Memorial Hospital (CGMH IRB 202401596B0) and was conducted in accordance with the ethical principles of the Helsinki declaration. As a result of the retrospective nature of the study, the need to obtain written informed consent was waived. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Very-low-birth-weight infants (VLBW, < 1500 g) are at risk of developing bronchopulmonary dysplasia (BPD) and are at risk for BPD-related pulmonary hypertension (PH). The longitudinal measurement of innovative blood and echocardiographic biomarkers might allow for a risk stratification of these infants. A prospective single-center cohort study was conducted between 01/2021 and 06/2023. Inclusion criteria were the combination of a birth weight < 1500 g and a gestational age (GA) ≤ 30/0 weeks. Assessment timepoints: T1 (day 7), T2 (day 28), and T3 (at 36 weeks post-menstrual age, PMA). Overall, 71 preterm infants were included for final analysis. The Zlog-transformed NTproBNP Zlog (at T1 AUC 0.772; p = 0.019; at T2 AUC 0.874, p = 0.002), and endothelin-1 (ET1, at T1 AUC 0.789, p = 0.013) were identified as an early predictive biomarker for BPD/death in the univariate analysis. Additionally, echocardiographic markers of ventricular function and PH at T1 were predictive for BPD/death in the univariate analysis, with the highest predictivity found for the tricuspid annular plane systolic excursion-TAPSE (AUC 0.748, p = 0.016) and the pulmonary artery acceleration time to right ventricular ejection time (PAAT/RVET; AUC 0.744, p = 0.043). Regarding predictability of mortality alone NTroBNP Zlog (at T1 AUC 0.973, p = 0.000), and CA125 (at T1 AUC 0.747, p = 0.008) were identified as potential predictors, as well as TAPSE (AUC 0.926, p = 0.000), and PAAT/RVET (AUC 0.985, p = 0.000) Several biomarkers including ET-1 (at T1 AUC 0.893, p = 0.000), TAPSE (AUC 0.974, p = 0.000), and PAAT/RVET (AUC 1.0, p = 0.000) at T1 were identified as univariate predictors for BPD-PH. In the multivariate analysis, no biomarker was identified as an independent predictor of the primary endpoint., Conclusion: Mainly at an early stage of postnatal neonatal care in VLBW preterm infants, several biomarkers were found to be associated with the combined endpoint BPD/death and BPD-PH. New candidates of blood biomarkers (NTproBNPZ log , ET-1, and CA125) and echocardiographic markers (TAPSE, PAAT/RVET) might serve as innovative predictors for BPD, BPD-PH, and adverse outcomes in VBLW infants., What Is Known: • VLBW infants are at risk for the development of BPD and BPD-related PH, which both are main contributors for short and long-term morbidity and mortality. Several studies in the past focused on the evaluation of circulating blood biomarkers and biomarkers from echocardiographic assessment of these infants. But to date, there is still a lack on longitudinal prospective studies especially in VLBW infants., What Is New: • For the first time, this set of selected blood biomarkers (with the first description of Zlog-transformed NTproBNP and CA125 in preterm infants) and several echocardiographic markers were analyzed in a prospective longitudinal study from birth until 36 weeks post menstrual age in VLBW infants. Our data help clinicians to identify preterm infants at risk for BPD, BPD-PH and death and to offer new candidates of biomarkers. This might help to facilitate decision making and guidance of therapy in these highly vulnerable patients., Competing Interests: Declarations Ethics approval and consent to participate The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Institutional Review of the Medical Center of the University of Bonn (local running number 011/19). Patients were prospectively enrolled in the study after informed written consent was obtained from the parents or legal representative. The methods used for the clinical research were performed in accordance with the STROBE (strengthening the reporting of observational studies in epidemiology) guidelines [13] and in accordance with the Declaration of Helsinki. The study was registered at the German Clinical Trials Register (GCT; trial number DRKS00033219). Consent statement All legal guardians of the participants of the present study signed a consent form prior to study inclusion according to the local guidelines of the ethical committee. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background: Research in functional asymmetry of Major Depressive Disorder (MDD) under different tasks is crucial for clinical diagnose., Methods: Fifty individuals with MDD and twenty healthy controls (HCS) were recruited for hemodynamic data collection under four fNIRS tasks (Emotional picture, Verbal fluency, Fingering and Negative emotional picture description task). Integral values and functional connectivity strength were employed to probe neural activation and functional connectivity in frontal and temporal lobes in MDD. Following, asymmetry characteristic of the frontal cortex between MDD and HCS under four tasks were carefully analyzed and compared., Results: Individuals with MDD demonstrated heightened connectivity between the frontal and right temporal lobes and reduced connectivity between the frontal and left temporal lobes compared to HCS in all tasks. Additionally, MDD exhibited attenuated activation in the left frontal lobes and exaggerated activation in the right frontal lobes, diverging from HCS. Furthermore, the disparities in left-right asymmetry characteristic of frontal cortex activation between MDD and HCS were more pronounced during the combined task., Limitations: Further research is required to grasp the neurophysiological mechanisms governing left-right asymmetry across various tasks and the influence of task-induced brain fatigue on cerebral cortex hemodynamics in MDD., Conclusion: The left-right asymmetry feature provides valuable neurophysiological insights for diagnosing MDD clinically. Variations in activation patterns and functional connectivity features between MDD and HCS are closely tied to the task chosen. Thus, in clinical practice, carefully selecting appropriate fNIRS tasks and relevant features can significantly improve the diagnostic accuracy of MDD., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The prognosis of myocardial infarction with non-obstructive coronary arteries (MINOCA) is reported to be as worse as myocardial infarction with obstructive coronary arteries. However, its mechanical complications are still poorly understood. A 71-year-old woman developed MINOCA after ascending aortic replacement surgery. During treatment, the patient experienced cardiogenic shock due to a ventricular septal rupture (VSR). The introduction of Impella devices reduced the left-to-right shunt and improved the patient's hemodynamics. Finally, a scheduled surgical repair was performed under stable conditions. In this report, we focused on the pathophysiology of MINOCA-related VSR and discussed the effectiveness of Impella devices as a bridge to surgical repair and circulatory backup during the perioperative period.

As more women engage in high-altitude activities, understanding how ovarian hormone fluctuations affect their cardiorespiratory system is essential for optimizing acclimatization to these environments. This study investigates the effects of menstrual cycle (MC) phases on physiological responses at rest, during and after submaximal exercise, at high-altitude (barometric pressure 509 ± 6 mmHg; partial pressure of inspired oxygen 96 ± 1 mmHg; ambient temperature 21 ± 2 °C and relative humidity 27 ± 4%) in 16 eumenorrheic women. Gas exchange, hemodynamic responses, heart rate variability and heart rate recovery (HRR) were monitored at low altitude, and then at 3375 m on the Mont Blanc (following nocturnal exposure) during both the early-follicular (EF) and mid-luteal (ML) phases. Significant differences were observed between low and high-altitude in ventilation, heart rate and cardiac output. Resting ventilation (15.2 ± 1.9 vs. 13.2 ± 2.5 L.min -1 ; p = 0.039) and tidal volume (812 ± 217 vs. 713 ± 190 mL; p = 0.027) were higher during EF than ML at high-altitude. These differences between EF and ML were no longer evident during exercise, with comparable responses in oxygen uptake kinetics, cycling efficiency and HRR. The MC had negligible effects on physiological responses to high-altitude. An individualized approach, tailored to each woman's specific responses to hypoxia across the MC, may be more beneficial in optimizing high-altitude sojourns than general guidelines., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Purpose: To present a first principle-based, high-fidelity computational model for predicting full three-dimensional (3D) and time-resolved retinal microvascular hemodynamics taking into consideration the flow and deformation of individual blood cells., Methods: The computational model is a 3D fluid-structure interaction model based on combined finite volume/finite element/immersed-boundary methods. Three in silico microvascular networks are built from high-resolution in vivo motion contrast images of the superficial capillary plexus in the parafoveal region of the human retina. The maximum tissue area represented in the model is approximately 500 × 500 µm2, and vessel lumen diameters ranged from 5.5 to 25 µm covering capillaries, arterioles, and venules. Blood is modeled as a suspension of individual blood cells, namely, erythrocytes (RBC), leukocytes (WBC), and platelets in plasma. An accurate and detailed biophysical modeling of each blood cell and their flow-induced deformation is considered. A physiological, pulsatile boundary condition corresponding to an average cardiac cycle of 0.9 second is used., Results: Detailed quantitative data and analysis of 3D retinal microvascular hemodynamics are presented, and their relationship to RBC flow dynamics is illustrated. Blood velocity is shown to have temporal oscillations superimposed on the background pulsatile variation, which arise because of the way RBCs partition at vascular junctions, causing repeated clogging and unclogging of vessels. Temporal variations in RBC velocity and hematocrit are anti-correlated in a given vessel, but their time-averaged distributions are positively correlated across the network. Whole blood velocity is 65% to 85% of RBC velocity, with the discrepancy related to the formation of an RBC-free region, adjacent to the vascular endothelium and typically 0.8 to 1.8 µm thick. The 3D velocity and RBC concentration profiles are shown to be oppositely skewed with respect to each other, because of the way that RBCs "hug" the apex of each bifurcation. RBC deformation is predicted to have biphasic behavior with respect to vessel diameter, with minimal cell length for vessels approximately 7 µm in diameter. The wall shear stress (WSS) exhibits a strongly 3D distribution with local regions of high value and gradient spanning a range of 10 to 80 dyn/cm2. WSS is highest where there is faster flow, greater curvature of the vessel wall, capillary bifurcations, and at locations of RBC crowding and associated thinning of the cell-free layer., Conclusions: This study highlights the usefulness of high-fidelity cell-resolved modeling to obtain accurate and detailed 3D, time-resolved retinal hemodynamic parameters that are not readily available through noninvasive imaging approaches. The results presented are expected to complement and enhance the interpretation of in vivo data, as well as open new avenues to study retinal hemodynamics in health and disease.

Objective: Acute treatment in mild stroke patients with acute anterior circulation large vessel occlusion/stenosis (AACLVO/S) had limited evidence. Hemodynamic play an important role in neurological deterioration. We aimed to investigate predictor value of hemodynamic assessment for clinical outcome predicting and guiding individual therapeutic decisions in those patients., Methods: We retrospectively analyze the stroke database in our stroke center. We recruited patients with mild stroke, defined by National Institutes of Health Stroke Scale (NIHSS) score ≤ 5, caused by AACLVO/S treated with just medical management (MT). They all received cerebral autoregulation (CA) assessments within 72 h after stroke onset. The primary end point was clinical outcome at 90-day after stroke., Results: Logistic regression analysis showed that bilateral higher baseline phase difference (PD) were independent variables related to favorable 90-day outcome, (OR 0.963, 95% CI 0.936-0.991, p = 0.040; OR 0.943, 95% CI 0.970-0.997; p = 0.008, respectively). The optimal cutoff value of bilateral PD was > 34.97º and > 14.29º respectively., Conclusion: CA evaluation can provide hemodynamic status in mild stroke patients with AACLVO/S., (© 2024. The Author(s).)

Patients with acute brain injury (ACI) often require mechanical ventilation (MV) and are subject to pulmonary complications, thus justifying the use of Airway Clearance Techniques (ACTs), but their effects on intracranial pressure (ICP) are unknown. This study investigates the neurological and hemodynamics safety of an ACT called ventilator hyperinflation (VHI) in patients with ACI. This was a randomized clinical equivalence trial, which included patients aged ≥ 18 years with a clinical diagnosis of hemorrhagic stroke, with symptom onset within 48 h. The participants were randomly allocated to the Experimental Group (EG, n = 15), which underwent VHI followed by tracheal aspiration (TA), and the Control Group (CG, n = 15), which underwent TA only. Neurological safety was verified by analyzing the morphology of the ICP wave through the non-invasive B4C sensor, which detects bone deformation of the skull, resulting in a P2/P1 ratio and TTP, and hemodynamics through a multi-parameter monitor. Evaluations were recorded during five instances: T1 (baseline/pre-VHI), T2 (post-VHI and before TA), T3 (post-TA), T4 and T5 (monitoring 10 and 20 min after T3). The comparison between groups showed that there was no effect of the technique on the neurological variables with a mean P2/P1 ratio [F (4,112) = 1.871; p = 0.120; np2 = 0.063] and TTP [F (4,112) = 2.252; p = 0.068; np2 = 0.074], and for hemodynamics, heart rate [F (4,112) = 1.920; p = 0.112; np2 = 0.064] and mean arterial pressure [F(2.73, 76.57) = 0.799; p = 0.488; np2 = 0.028]. Our results showed that VHI did not pose a neurological or hemodynamics risk in neurocritical patients after ACI.

Mechanical circulatory support is a potential treatment for failing Fontan patients. In this study, we performed a theoretical analysis using a computational model to clarify the effects of systemic ventricular assist device (VAD) in failing Fontan patients. Cardiac chambers and vascular systems were described using the time-varying elastance model and modified Windkessel model, respectively. A VAD was simulated as a nonlinear function. In systolic and diastolic ventricular dysfunction and atrioventricular valve regurgitation models, systemic VAD increased the cardiac index and decreased the central venous pressure (CVP). However, in the high pulmonary vascular resistance model, CVP became extremely high above 15 mmHg to maintain the cardiac index when the pulmonary vascular resistance index (PVRI) was above 5 Wood units m 2 . In Fontan patients with ventricular dysfunction or atrioventricular valve regurgitation, systemic VAD efficiently improves the hemodynamics. In Fontan patients with PVRI of > 5 Wood units m 2 , systemic VAD seems ineffective., (© 2024. The Author(s).)

Objective: This study explored the feasibility of using high-frame-rate ultrasound vector flow imaging (VFI) to quantitatively assess hemodynamics in atherosclerotic internal carotid artery stenosis (ICAS) by evaluating dual-parameters, turbulence index (Tur), and wall shear stress (WSS). Their efficacy in evaluating carotid artery stenosis was also analyzed., Methods: Fifty-nine patients with ICAS were enrolled. B-mode ultrasound and V Flow (a high-frame-rate VFI) were performed using the Resona R9 system. The stenosis rate was measured in grayscale mode, whereas the time-averaged Tur index, the time-averaged WSS (WSS mean ), and maximum WSS (WSS max ) around stenosis were measured. The combined diagnostic efficacy of Tur inand WSS was also investigated., Results: Compared to proximal to stenosis (Tur index, 2.88% ± 3.65%), highly disordered blood flow was observed in the stenotic (23.17% ± 15.52%, p < 0.001) and distal segment (25.86% ± 17.29%, p < 0.001). WSS max ([11.91 ± 6.73] vs. [4.43 ± 5.4] Pa, p < 0.001) and WSS mean ([3.42 ± 2.67] vs. [0.86 ± 1.21] Pa, p < 0.001) were significantly bigger in stenotic than those in the distal segment. The differences in the ratio WSS max /Tur or WSS mean /Tur among different segments around stenosis were statistically significant (p < 0.001). The combination of Tur index and WSS had the best diagnostic performance in ICAS (AUC, 0.899)., Conclusion: The application of Tur index and WSS for quantitative assessment of ICAS hemodynamic changes is feasible, with the combined evaluation of these two parameters providing incremental diagnostic value for carotid artery stenosis. VFI-based dual quantitative parameters may offer promising noninvasive diagnostic tools for carotid artery stenosis in high-stroke-risk populations., (© 2024 The Author(s). Brain and Behavior published by Wiley Periodicals LLC.)

Perfusion changes in white matter (WM) lesions and normal-appearing brain regions play an important pathophysiological role in multiple sclerosis (MS). However, most perfusion imaging methods require exogenous contrast agents, the repeated use of which is discouraged. Using resting-state functional MRI (rs-fMRI), we aimed to investigate differences in perfusion between white matter lesions and normal-appearing brain regions in MS and healthy participants. A total of 41 MS patients and 41 age- and sex-matched healthy participants received rs-fMRI, from which measures of cerebral hemodynamics and oxygenation were extracted and compared across brain regions and study groups using within- and between-group nonparametric tests, linear mixed models, and robust multiple linear regression. We found longer blood arrival times and lower blood volumes in lesions than in normal-appearing WM. Higher blood volumes were found in MS patients' deep WM lesions compared to healthy participants, and blood arrival time was more delayed in MS patients' deep WM lesions than in healthy participants. Delayed blood arrival time in the cortical grey matter was associated with greater cognitive impairment in MS patients. Perfusion imaging using rs-fMRI is useful for WM lesion characterization. rs-fMRI-based blood arrival times and volumes are associated with cognitive function., (© 2024 The Author(s). Human Brain Mapping published by Wiley Periodicals LLC.)

Heart failure (HF) is a syndrome affecting all organ systems. While some organ interactions have been studied intensively in HF (such as the cardiorenal interaction), the endocrine gut has to some degree been overlooked. However, there is growing evidence of direct cardiac effects of several hormones secreted from the gastrointestinal tract. For instance, GLP-1 (glucagon-like peptide-1), an incretin hormone secreted from the distal intestine following food intake, has notable effects on the heart, impacting heart rate and contractility. GLP-1 may even possess cardioprotective abilities, such as inhibition of myocardial ischemia and cardiac remodeling. While other gut hormones have been less studied, there is evidence suggesting cardiostimulatory properties of several hormones. Moreover, it has been reported that patients with HF have altered bioavailability of numerous gastrointestinal hormones, which may have prognostic implications. This might indicate an important role of gut hormones in cardiac physiology and pathology, which may be of particular importance in the failing heart. We present an overview of the current knowledge on gut hormones in HF, focusing on HF with reduced ejection fraction, and discuss how these hormones may be regulators of cardiac function and central hemodynamics. Potential therapeutic perspectives are discussed, and knowledge gaps are highlighted herein., Competing Interests: Dr Kistorp reports honoraria for advisory boards and speaker’s fees from Sanofi Genzyme, Amicus, and Chiesi and speakers fees from Boehringer Ingelheim. Dr Gustafsson reports honoraria for advisory roles from Abbott, AstraZeneca, Ionis, Pfizer, Bayer, CorWave, and AdjuCor and speaker’s fee from Novartis. Dr Goetze reports no conflicts.

Functional magnetic resonance imaging (fMRI) has been widely used in studying the neural mechanisms of pain in the human brain, primarily focusing on where in the brain pain-elicited neural activities occur (i.e., the spatial distribution of pain-related brain activities). However, the temporal dynamics of pain-elicited hemodynamic responses (HDRs) measured by fMRI may also contain information specific to pain processing but have been largely neglected. Using high temporal resolution fMRI (TR = 0.8 s) data acquired from 62 healthy participants, in the present study we aimed to test whether pain-distinguishing information could be decoded from the spatial pattern of the temporal dynamics (i.e., the spatiotemporal pattern) of HDRs elicited by painful stimuli. Specifically, the peak latency and the response duration were used to characterize the temporal dynamics of HDRs to painful laser stimuli and non-painful electric stimuli, and then were compared between the two conditions (i.e., pain and no-pain) using a voxel-wise univariate analysis and a multivariate pattern analysis. Furthermore, we also tested whether the two temporal characteristics of pain-elicited HDRs and their spatial patterns were associated with pain-related behaviors. We found that the spatial patterns of HDR peak latency and response duration could successfully discriminate pain from no-pain. Interestingly, we also observed that the Pain Vigilance and Awareness Questionnaire (PVAQ) scores were correlated with the average response duration in bilateral insula and secondary somatosensory cortex (S2) and could also be predicted from the across-voxel spatial patterns of response durations in the middle cingulate cortex and middle frontal gyrus only during painful condition but not during non-painful condition. These findings indicate that the spatiotemporal pattern of pain-elicited HDRs may contain pain-specific information and highlight the importance of studying the neural mechanisms of pain by taking advantage of the high sensitivity of fMRI to both spatial and temporal information of brain responses., (© 2024 The Author(s). Human Brain Mapping published by Wiley Periodicals LLC.)

Ensuring adequate and stable hemodynamic conditions is an essential component of patient care in emergency and intensive care units. The assessment of circulatory status is complex and influenced by patient-specific characteristics, medical staff experience, and available equipment. Hemodynamic monitoring encompasses both invasive and noninvasive methods to monitor circulatory parameters. It supports patient management and ensures therapeutic success by alerting healthcare providers to deviations, including critical values. In practice, numerical data often receive more emphasis than comprehensive patient observation, potentially leading to misinterpretation. Advanced practice nurses (APNs) are highly qualified nursing professionals who work largely autonomously due to their advanced training. However, there is currently no uniform legal regulation for these professions in Germany. Clear definitions and nationwide regulations for related academic programs are necessary. Interprofessional collaboration, as well as the qualifications and numbers of nursing staff, significantly impact therapeutic outcomes. Hemodynamics involves the physical principles of blood flow and the assessment of vital parameters to ensure organ perfusion and oxygenation. The competence and knowledge of nursing staff are crucial for safe patient care. Local standard operating procedures (SOPs) should consider interprofessional collaboration and the qualifications of team members., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Dorset sheep (Ovis aries) are common models in translational cardiovascular research due to physiologic and anatomic similarities to humans. While employing ovine subjects to study single-ventricle physiology, we repeatedly observed position-based changes in central venous pressure (CVP) which could not be explained by hydrostatic (gravitational) effects. Inferior vena cava (IVC) narrowing or compression has been demonstrated in numerous species, and we hypothesised that this phenomenon might explain our observations in O. aries. This study aimed to characterise position-dependent morphology of the IVC in O. aries using catheter-based hemodynamic and dimensional measurements, three-dimensional MRI reconstruction and histological analysis. Baseline measurements revealed a significant reduction in IVC dimensions at the level of the diaphragm (dVC) compared to the abdominal vena cava (aVC) and thoracic vena cava (tVC). We also observed a transdiaphragmatic pressure gradient along the IVC, with higher pressures in the aVC compared to the tVC. We found that variation of position and fluid status altered IVC haemodynamics. Histological data showed variable muscularity along the length of the IVC, with greater smooth muscle content in the aVC than the tVC. These findings will improve understanding of baseline ovine physiology, help refine experimental protocols and facilitate the translation of findings to the clinic., (© 2024 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.)

Objective: This study undertook neuropharmacological research on the clinical course of controlled medication discontinuation to guide practitioners who are considering stopping medications for youths with attention-deficit hyperactivity disorder (ADHD)., Methods: This study analyzed the data for 14 ADHD children (12 male and 2 female) in two datasets: The children prescribed methylphenidate (MPH) were at an initial mean age of 7.5 years (SD = 1.70, range: 6-11) with a mean ADHD-Rating Score (ADHD-RS) of 26.6 (SD = 8.64, range 15-40). The children who discontinued MPH based on clinical judgment were at a mean age of 12.21 years (SD = 2.12, range: 8-15) with a mean ADHD-RS of 15.9 (SD = 6.86, range 5-27). The go/no-go task was used to assess response inhibition, while functional near-infrared spectroscopy (fNIRS) was used to measure cerebral hemodynamics. Oxygenated hemoglobin (Oxy-Hb) values from fNIRS data were analyzed for each subject, focusing on past and current measurements. Baseline was set at 10 s pre-task, with interval means from 4 to 24 s analyzed. One-sample t-tests were used to evaluate brain activity magnitude., Results: The results of the study demonstrate that the children who had discontinued the medication exhibited activation in specific brain regions including the frontopolar cortex and the right ventrolateral prefrontal cortex. Activation (t = 2.363, p = 0.034, Cohen's d = 0.632) was found especially in the right dorsolateral prefrontal cortex during the performance of the go/no-go task. These activated areas were consistent with those observed in a previous study comparing brain activity during a go/no-go task between children with ADHD and healthy children., Conclusion: The present study showed differences in cerebral hemodynamics before and after discontinuation of MPH in ADHD children whose ADHD symptoms did not recur after MPH was discontinued. In the near future, further investigations that include control groups will be conducted to demonstrate the effects of MPH prior to discontinuation based on the changes in cerebral blood flow in the right prefrontal cortex, which is involved in behavioral inhibition, as observed in this study. This and future research will facilitate the development of criteria for discontinuing treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced or appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Sonography, in particular echocardiography, is essential in the assessment of volume status and hemodynamics in critically ill patients. Examination of the left ventricle, in addition to assessing ventricular function, provides valuable information, including the "kissing papillary muscle sign," which may indicate fluid responsiveness. Examination of the right ventricle is also important because it is sensitive to both volume and pressure overload. Assessment of diastolic function and measurement of inferior vena cava width and variability provide clues to left and right ventricular preload, respectively. Measurement of stroke volume and cardiac output allows further assessment of hemodynamics and also permits determination of stroke volume variability., (© 2024. The Author(s).)

The ROSE concept, which is the acronym of resuscitation, optimization, stabilization and evacuation, describes the phases of fluid therapy, based on the pathophysiology of septic shock. During the first two phases, aggressive fluid therapy that is guided by clinical and hemodynamic parameters is mandatory. During the stabilization phase, recovery from shock and microcirculatory injury occurs, which enables the depletion of fluid overload in the fourth and final phase. Ultimately, euvolemia needs to be regained, which reverts interstitial edema and organ dysfunction., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Although the hemodynamics of cerebral aneurysms have been extensively studied using patient-specific computational fluid dynamics techniques, no specific hemodynamic factors characteristic of cerebral aneurysm development have yet been identified. We believe that one problem with previous hemodynamic studies of cerebral aneurysms has been the manner in which control groups were created for comparison with experimental groups. The purpose of this study was to determine hemodynamic factors that correlated with the development of cerebral aneurysms. The control group was established in a manner that differed from those of previous works. This allowed us to demonstrate the effectiveness of our method. We artificially removed aneurysms in the middle cerebral artery bifurcations of nine patients and reconstructed the vessel geometries before the aneurysms had occurred. Pulsatile blood flow simulations were performed using the vessel geometries ipsilateral and contralateral to the sites of aneurysm removal, and hemodynamic metrics were calculated. Use of the ipsilateral and contralateral sides as the experimental and control sites, respectively, allowed us to evaluate statistically the hemodynamic metrics between the two corresponding sites/groups. The results showed that only the normalized transverse wall shear stress (NtransWSS) was significantly higher at the MCA bifurcation ipsilateral to the site of aneurysm removal than at the contralateral bifurcation (p = 0.01). There were no significant differences in the other hemodynamic metrics between the bilateral bifurcations. Our findings imply that multi-directional disturbed wall shear stress, which is detected by the NtransWSS metric, may be one hemodynamic risk factor for the development of cerebral aneurysms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

One of the growing challenges to public health and clinical outcomes is the emergence of cognitive impairments, particularly depressive symptom severity, because of chronic elevations in metabolic disease and cerebrovascular disease risk. To more clearly delineate these relationships and to assess the potential for sexual dimorphism, we used lean (LZR) and obese Zucker rats (OZR) of increasing age to determine relationships between internal carotid artery (ICA) hemodynamics, cerebral vasculopathies, and the emergence of depressive symptoms. Male OZR exhibited progressive elevations in perfusion pressure within the ICA, which were paralleled by endothelial dysfunction, increased cerebral arterial myogenic activation, and reduced cerebral cortex microvessel density. In contrast, female OZR exhibited a greater degree of ICA hypertension than male OZR but maintained normal endothelial function, myogenic activation, and microvessel density to an older age range than did males. Although both male and female OZR exhibited significant and progressive elevations in depressive symptom severity, these were significantly worse in females. Finally, plasma cortisol concentration was elevated higher and at a younger age in female OZR as compared with males, and this difference was maintained to final animal usage at ∼17 wk of age. These results suggest that an increased severity of blood pressure waves may penetrate the cerebral circulation more deeply in female OZR than in males, which may predispose the females to a more severe emergence of depressive symptoms with chronic metabolic disease, whereas males may be more predisposed to more direct cerebral vasculopathies (e.g., stroke, transient ischemic attack). NEW & NOTEWORTHY We provide novel insight that the superior maintenance of cerebrovascular endothelial function in female versus male rats with chronic metabolic disease buffers myogenic activation of cerebral resistance arteries/arterioles despite worsening hypertension. As hypertension development is earlier and more severe in females, potentially due to an elevated stress response, the blunted myogenic activation allows greater arterial pressure wave penetrance into the cerebral microcirculation and is associated with accelerated emergence/severity of depressive symptoms in obese female rats.

Background: Critically ill patients in the intensive care unit require intensified monitoring to control the treatment with volume and/or vasoactive substances., Research Question: What role does functional hemodynamic monitoring play in controlling treatment and what techniques are used to manage this?, Material and Methods: Review of the current literature., Results and Discussion: Precise knowledge of the physiology of the cardiovascular system as well as the pathophysiology of individual clinical pictures and the possibilities of invasive and noninvasive monitoring are the prerequisites for the indications, implementation and interpretation of functional hemodynamic monitoring. An understanding of the heart-lung interaction and the influence of invasive ventilation on the volumetric target parameters, such as stroke volume variation, systolic pressure variation and pulse pressure variation as well as sonography of the inferior vena cava are indispensable prerequisites for the question of volume responsiveness. Other maneuvers, such as the passive leg raising test, can be very helpful when deciding on volume administration in everyday clinical practice. Static parameters such as central venous pressure generally play no role and if any only a subordinate one., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

The spleen constantly clears altered red blood cells (RBCs) from the circulation, tuning the balance between RBC formation (erythropoiesis) and removal. The retention and elimination of RBCs occur predominantly in the open circulation of the spleen, where RBCs must cross submicron-wide inter-endothelial slits (IES). Several experimental and computational studies have illustrated the role of IES in filtrating the biomechanically and morphologically altered RBCs based on a rigid wall assumption. However, these studies also reported that when the size of IES is close to the lower end of clinically observed sizes (less than 0.5 μm), an unphysiologically large pressure difference across the IES is required to drive the passage of normal RBCs, sparking debates on the feasibility of the rigid wall assumption. In this work, We propose two deformable IES models, namely the passive model and the active model, aiming to explore the impact of the deformability of IES on the filtration function of the spleen. In the passive model, we implement the worm-like string model to depict the IES's deformation as it interacts with blood plasma and allows RBC to traverse. In contrast, the active model involved regulating the IES deformation based on the local pressure surrounding the slit. To demonstrate the validity of the deformable model, we simulate the filtration of RBCs with varied size and stiffness by IES under three scenarios: (1) a single RBC traversing a single slit; (2) a suspension of RBCs traversing an array of slits, mimicking in vitro spleen-on-a-chip experiments; (3) RBC suspension passing through the 3D spleen filtration unit known as'the splenon'. Our simulation results of RBC passing through a single slit show that the deformable IES model offers more accurate predictions of the critical cell surface area to volume ratio that dictate the removal of aged RBCs from circulation compared to prior rigid-wall models. Our biophysical models of the spleen-on-a-chip indicate a hierarchy of filtration function stringency: rigid model > passive model > active model, providing a possible explanation of the filtration function of IES. We also illustrate that the biophysical model of 'the splenon' enables us to replicate the ex vivo experiments involving spleen filtration of malaria-infected RBCs. Taken together, our simulation findings indicate that the deformable IES model could serve as a mesoscopic representation of spleen filtration function closer to physiological reality, addressing questions beyond the scope of current experimental and computational models and enhancing our understanding of the fundamental flow dynamics and mechanical clearance processes within in the human spleen., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Obstetric sepsis is a significant cause of morbidity and mortality in pregnant people worldwide. Initial evaluation and timely intervention are crucial to improving outcomes for birthing persons and their newborns. While many of the therapies and interventions for peripartum sepsis are consistent with the general population, there are considerations unique to pregnancy. Stabilization of the septic pregnant or immediately postpartum patient requires an understanding of the physiologic changes of pregnancy, hemodynamic changes during labor, and infections specific to pregnancy. We will review the interaction between pregnant physiology and sepsis pathophysiology, and how this can guide screening and diagnosis., (Copyright © 2024. Published by Elsevier Inc.)

Objective: Neovascularization has been extensively studied because of its significant role in both physiological processes and diseases. The significance of vascular microfluidic platforms lies in its essential role in recreating an in vitro environment capable of supporting cellular and tissue systems through the process of neovascularization. Biomechanical properties in a tissue engineered system use fluid flow and transport properties to recapitulate physiological systems. This enables mimicry of organ systems which can further personalized and regenerative medicine. Thus, fluid hemodynamics can be used to study these flow patterns and create a system that mimics real physiological pathways and processes. The establishment of stable flow pathways encourages endothelial cells (ECs) ECs to undergo neovascularization. Specifically, the shear stress applied in capillary beds generates the increased proliferation and differentiation of ECs to build larger microcirculatory beds., Mathematical Framework: Here, we describe a mathematical model that uses branching patterns and vessel morphology to predict hemodynamic parameters in capillary beds., Results: A retinal capillary bed is used as one-use case of our model to show how the mathematical framework can be used to determine hemodynamic parameters for any microfluidic system., Conclusion: In doing so, this tool can be altered to be used to supplement emerging research areas in neovascularization., (© 2024 John Wiley & Sons Ltd.)

Despite recent clinical and technological advancements, the cardiac arrest survival rate remains as low as 10%. To enhance patient outcomes, it is crucial to deepen the understanding of cardiopulmonary resuscitation (CPR) at a fundamental level. Currently, there is a lack of knowledge on the physiological effects of CPR, in particular on the hemodynamics in the heart and the great vessels. The design and validation of a dedicated in vitro heart simulator, capable of replicating the physiological response to CPR, holds the potential to provide valuable insights into the fluid dynamics in the heart during CPR but also to be used as a platform for the development and testing of mechanical CPR machines. The main objective of this study is to design and validate the first in vitro heart simulator that can replicate the physiological response during CPR. For that, a custom-made heart simulator is designed consisting of an elastic model of the complete heart and a controllable linear actuator. The heart model is positioned in an anatomical position, and the linear actuator compresses the model at specific rates and depths. Flow and pressure waveforms are recorded on the newly developed simulator at 60 contractions per minute and results are validated against reported in vivo data in the literature. Finally, the system's capabilities are evaluated by considering several combinations of compression rates and depths., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Ultramarathon participation is growing in popularity and exposes runners to unique stressors including extreme temperatures, high altitude, and exceedingly long exercise duration. However, the acute effects of ultramarathon participation on the cardiovascular system are not well understood. To determine the acute effects of trail ultramarathon participation on central artery stiffness and hemodynamics, 41 participants (9 F, 32 M) participating in the 2023 Western States Endurance Run underwent measures of carotid-femoral pulse wave velocity (cf-PWV) and pulse wave analysis pre- and <1 h post-race. Subendocardial viability ratio (SEVR) was calculated from central blood pressure (BP) waveforms. Serum was analyzed for creatine kinase (CK) activity as a measure of muscle damage. Normally distributed data are presented as means ± standard deviation (SD), and nonnormally distributed data are presented as median (interquartile range). Runners were middle-aged and generally lean [age = 44 ± 9 yr, body mass index (BMI) = 22.7 ± 1.8 kg·m -2 ]. There was no difference in cf-PWV from pre- to post-race (pre = 6.4 ± 1.0, post = 6.2 ± 0.85 m/s, P = 0.104), a finding that persisted after adjusting for mean arterial pressure ( P = 0.563). Systolic and diastolic BPs were lower post-race (pre = 129/77 ± 9/7, post = 122/74 ± 10/8 mmHg, P < 0.001). Augmentation index (AIx; pre = 17.3 ± 12.2, post = 6.0 ± 13.7%, P < 0.001), AIx normalized to a heart rate of 75 beats/min ( P = 0.043), reflection magnitude (pre = 55.5(49.0-60.8), post = 45.5(41.8-48.8)%, P < 0.001), and SEVR (pre = 173.0(158.0-190.0), post = 127.5(116.5-145.8)%, P < 0.001) were reduced post-race. CK increased markedly from pre- to post-race (pre = 111(85-162), post = 11,973(5,049-17,954) U/L, P < 0.001). Completing a 161-km trail ultramarathon does not affect central arterial stiffness and acutely reduces BP despite eliciting profound muscle damage. However, the reduced post-race SEVR suggests a short-term mismatch between myocardial work and coronary artery perfusion. NEW AND NOTEWORTHY Ultramarathon participation is growing dramatically. However, the acute cardiovascular effects of completing a 161-km trail ultramarathon remain unknown. We examined the acute effects of completing the 2023 Western States Endurance Run on arterial stiffness and central hemodynamics in a relatively large sample of males and females. We observed dramatic postexercise hypotension, reductions in reflected wave amplitude and reduced subendocardial viability ratio post-race. These findings suggest that ultramarathon participation has few negative effects on cardiovascular health.

The etiology of spaceflight-associated neuro-ocular syndrome (SANS) remains unclear. Recent murine studies indicate there may be a link between the space environment and retinal endothelial dysfunction. Post-fixed control (N = 4) and 14-day tail-suspended (TS) (N = 4) mice eye samples were stained and imaged for the vessel plexus and co-located regions of endothelial cell death. A custom workflow combined whole-mounted and tear reconstructed three-dimensional (3D) spherical retinal plexus models with computational fluid dynamics (CFD) simulation that accounted for the Fåhræus-Lindqvist effect and boundary conditions that accommodated TS fluid pressure measurements and deeper capillary layer blood flow distribution. TS samples exhibited reduced surface area (4.6 ± 0.5 mm 2 vs. 3.5 ± 0.3 mm 2 , P = 0.010) and shorter lengths between branches in small vessels (<10 μm, 69.5 ± 0.6 μm vs. 60.4 ± 1.1 μm, P < 0.001). Wall shear stress (WSS) and pressure were higher in TS mice compared to controls, particularly in smaller vessels (<10 μm, WSS: 6.57 ± 1.08 Pa vs. 4.72 ± 0.67 Pa, P = 0.034, Pressure: 72.04 ± 3.14 mmHg vs. 50.64 ± 6.74 mmHg, P = 0.004). Rates of retinal endothelial cell death were variable in TS mice compared to controls. WSS and pressure were generally higher in cell death regions, both within and between cohorts, but significance was variable and limited to small to medium-sized vessels (<20 μm). These findings suggest a link may exist between emulated microgravity and retinal endothelial dysfunction that may have implications for SANS development. Future work with increased sample sizes of larger species or spaceflight cohorts should be considered., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Generating 10-s (∼0.1 Hz) fluctuations or "oscillations" in arterial pressure and blood flow blunts reductions in cerebral tissue oxygenation in response to 15%-20% reductions in cerebral blood flow. To examine the effect of 0.1 Hz hemodynamic oscillations on tissue oxygenation during severe ischemia, we developed a partial limb ischemia protocol targeting a 70%-80% reduction in blood flow. We hypothesized that 0.1 Hz hemodynamic oscillations would attenuate reductions in tissue oxygenation during severe ischemia. Thirteen healthy humans (6 M and 7 F; 27.3 ± 4.2 yr) completed two experimental protocols separated by ≥48 h. In both conditions, an upper arm cuff was used to decrease brachial artery (BA) blood velocity by ∼70%-80% from baseline. In the oscillation condition (0.1 Hz), 0.1 Hz hemodynamic oscillations were induced by intermittently inflating and deflating bilateral thigh cuffs every 5 s during forearm ischemia. In the control condition (0 Hz), the thigh cuffs were inactive. BA blood flow, forearm tissue oxygenation (SmO 2 ), and arterial pressure were measured continuously. The initial reduction in BA blood velocity was tightly matched between protocols (0 Hz: -76.9 ± 7.9% vs. 0.1 Hz: -75.5 ± 7.4%, P = 0.49). Although 0.1 Hz oscillations during forearm ischemia had no effect on the reduction in BA velocity (0 Hz: -73.0 ± 9.9% vs. 0.1 Hz: -73.3 ± 8.2%, P = 0.91), the reduction in SmO 2 was attenuated (0 Hz: -35.7 ± 8.6% vs. 0.1 Hz: -27.2 ± 8.9%, P = 0.01). These data provide further evidence for the use of 0.1 Hz hemodynamic oscillations as a potential therapeutic intervention for conditions associated with severe tissue ischemia (e.g., hemorrhage and stroke). NEW & NOTEWORTHY We investigated the effects of induced 10-s (0.1 Hz) oscillations in blood flow on forearm tissue oxygenation during severe ischemia. Intermittent inflation of bilateral thigh cuffs was used as a clinically applicable method to drive blood flow oscillations. In support of our hypothesis, 0.1 Hz oscillations in blood flow blunted reductions in forearm tissue oxygenation. These results further support the potential use of oscillatory hemodynamics as a therapeutic intervention for ischemic conditions.

Background: This study seeks to quantify the effects of upper body veno-arterial extracorporeal membrane oxygenation (VA ECMO) on the anatomical distribution of oxygen delivery in the setting of hypoxic respiratory failure and provide new insights that will guide clinical use of this support strategy to bridge patients to lung transplant., Methods: Employing a patient-specific vascular geometry and a quantitative model of oxygen transport, computational simulations were performed to determine hemodynamics and oxygen delivery in the ascending and descending aorta, left and right coronary arteries, and great vessels during upper body VA ECMO support. Oxygen content in ECMO circuit blood flow was varied while considering different degrees of lung failure severity. Using lumped parameter models to dynamically apply perfusion boundary conditions, hemodynamic parameters and oxygen content were analyzed to assess the effect of ECMO supply titration., Results: The results emphasize the importance of anatomical distribution for tissue oxygen delivery in severe lung failure, with ECMO-derived flow primarily augmenting oxygen content in specific vascular beds. They also demonstrate that although cannulating the subclavian artery can enhance cerebral oxygen delivery, its ability to ensure sufficient oxygen delivery to the coronary circulation seems to be comparatively restricted., Conclusions: The oxygen delivery to a specific vascular area is primarily determined by the oxygen content in the source of perfusion. Caution is advised with upper body VA ECMO for patients with hypoxic respiratory failure and right ventricle dysfunction, due to potential coronary ischemia. Management of these patients is challenging due to disease progression and organ availability uncertainties., Competing Interests: Declaration of competing interest Hamed Moradi denies any competing interests. Raghu Seethala denies any competing interests. Elazer Edelman is the primary investigator of an educational grant to the Massachusetts Institute of Technology (MIT) from Abiomed, Inc. that investigates use of mechanical circulatory support devices. He has developed intellectual property that is licensed to Abiomed, Inc. through MIT. This work is in the related field of mechanical support but is not directly related to the submitted work. Farhad Nezami denies any competing interests. Steven Keller is a co-inventor of intellectual property with Dr. Edelman that is licensed to Abiomed, Inc. through MIT. This work is not directly related to the submitted work., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Vascular risk factors seem to contribute to disease progression in Multiple Sclerosis (MS), but the mechanistic connection between vascular risk and MS is unknown. Understanding cerebrovascular hemodynamics (CVH) in MS may help advance our understanding of the link between vascular risk and MS., Objectives: Examine the relationship between CVH [dynamic cerebral autoregulation (dCA) and vasoreactivity (VR)] and brain structure (MRI) and function (cognition, and gait) in individuals with MS., Methods: Transcranial Doppler ultrasound (TCD) was utilized to assess two key markers of CVH: dCA and VR. dCA (reported as phase and gain) is calculated from the spontaneous blood pressure and flow velocity oscillations. VR is calculated as the slope of change in cerebral blood flow velocity in response to end-tidal CO 2 . Global gray matter (GM), white matter (WM), WM hyperintensity (WMH) volumes and WM lesion counts were measured from brain MRI. All participants underwent detailed cognitive and gait assessments., Results: Eighty participants were included (age 44 ± 11, 26 % male); 75 had relapsing-remitting MS (94 %), with disease duration of 8 (11) years [median (IQR)] since MS diagnosis and an Expanded Disability Status Scale (EDSS) of 2.0 (4.0). Higher phase (better dCA) was associated with greater GM volume, lower WHM burden and higher cognitive scores in the memory and global cognitive domains (all P values <0.05). There was no relationship between CVH and gait speed in our study participants. There was no relationship between VR and any measures of brain structure and function., Conclusions: More efficient cerebral autoregulation is associated with better brain structure (larger GM and lower WMH volumes) and function (cognition, but not gait) in patients with MS., Competing Interests: Declaration of competing interest None., (Copyright © 2024. Published by Elsevier B.V.)

Splenic artery embolization (SAE) has become a favored alternative to splenectomy, offering a less invasive intervention for injured spleens while preserving spleen function. However, our understanding of the role that hemodynamics plays during embolization remains limited. In this study, we utilized patient-specific computational fluid dynamics (CFD) simulations to study distal and proximal embolization strategies commonly used in SAE. Detailed 3D computer models were constructed considering the descending aorta, various major visceral arteries, and the iliac arteries. Subsequently, the blood flow and pressure associated with different coil placement locations in proximal embolization were studied considering the collateral vessels. Coil induced variations in pressure fields were quantified and compared to baseline. The coil induced flow stagnation was also quantified with particle residence time. Distal embolization was modeled with Lagrangian particle tracking and the effect of particle size, release location, and timing on embolization outcome was studied. Our findings highlight the crucial role of collateral vessels in maintaining blood supply to the spleen following proximal embolization. It was demonstrated that coil location can affect distal pressure and that strategic coil placement guided by patient-specific CFD simulations can further reduce this pressure as desired. Additionally, the results point to the critical roles that particle size, release timing, and location play in distal embolization. Our study provides an early attempt to use patient-specific computer modeling for optimizing embolization strategies and ultimately improving patient outcomes during SAE procedures., Competing Interests: Declaration of competing interest The authors hereby declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Hemodynamic factors play an important role in the formation and rupture of intracranial aneurysms. Blood viscosity has been recognized as a potential factor influencing the hemodynamics of aneurysms. Computational fluid dynamics (CFD) is one of the main methods to study aneurysm hemodynamics. However, current CFD studies often set the viscosity to a standard value, neglecting the effect of individualized viscosity on hemodynamics. We investigate the impact of blood viscosity on hemodynamics in large intracranial aneurysm (IA) and assess the potential implications for aneurysm growth and rupture risk., Methods: CFD simulations of 8 unruptured large internal carotid artery aneurysms were conducted using pulsatile inlet conditions. For each aneurysm, CFD simulations were performed at 5 different viscosity levels (0.004, 0.006, 0.008, 0.010, and 0.012 Pa·s). Differences in hemodynamic parameters across viscosity levels were compared using paired t-tests, and the correlation between viscosity and hemodynamic parameters was analyzed., Results: Increasing blood viscosity leads to significant decrease in blood flow velocity within aneurysms. Time-averaged wall shear stress (WSS) showed significant positive correlation with viscosity, particularly at the aneurysm neck. Oscillatory shear index (OSI) showed general decreasing trend with increased viscosity, while it displayed an irregular pattern in a few cases., Conclusions: Variations in viscosity markedly influence velocity, WSS, and OSI in aneurysms, suggesting a role in modulating aneurysm growth and rupture risk. Incorporating patient-specific viscosity values in CFD simulations is vital for accurate and reliable outcomes., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Accurate prenatal diagnosis of coarctation of the aorta (CoA) is challenging due to high false positive rate burden and poorly understood aetiology. Despite associations with abnormal blood flow dynamics, fetal arch anatomy changes and alterations in tissue properties, its underlying mechanisms remain a longstanding subject of debate hindering diagnosis in utero. This study leverages computational fluid dynamics (CFD) simulations and statistical shape modelling to investigate the interplay between fetal arch anatomy and blood flow alterations in CoA. Using cardiac magnetic resonance imaging data from 188 fetuses, including normal controls and suspected CoA cases, a statistical shape model of the fetal arch anatomy was built. From this analysis, digital twin models of false and true positive CoA cases were generated. These models were then used to perform CFD simulations of the three-dimensional fetal arch haemodynamics, considering physiological variations in arch shape and blood flow conditions across the disease spectrum. This analysis revealed that independent changes in the shape of. the arch and the balance of left-to-right ventricular output led to qualitatively similar haemodynamic alterations. Transitioning from a false to a true positive phenotype increased retrograde flow through the aortic isthmus. This resulted in the appearance of an area of low wall shear stress surrounded by high wall shear stress values at the flow split apex on the aortic posterior wall opposite the ductal insertion point. Our results suggest a distinctive haemodynamic signature in CoA characterised by the appearance of retrograde flow through the aortic isthmus and altered wall shear stress at its posterior side. The consistent link between alterations in shape and blood flow in CoA suggests the need for comprehensive anatomical and functional diagnostic approaches in CoA. This study presents an application of the digital twin approach to support the understanding of CoA mechanisms in utero and its potential for improved diagnosis before birth., Competing Interests: Declaration of competing interest None declared., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: We examined whether brain hemodynamic responses, gait, and cognitive performances under single- and dual-task conditions predict falls during longitudinal follow-up in older adults with multiple sclerosis (OAMS) with relapsing-remitting and progressive subtypes., Methods: Participants with relapsing-remitting ( n = 53, mean age = 65.02 ± 4.17 years, %female = 75.5) and progressive ( n = 28, mean age = 64.64 ± 4.31 years, %female = 50) multiple sclerosis (MS) subtypes completed a dual-task-walking paradigm and reported falls during longitudinal follow-up using a monthly structured telephone interview. We used functional near-infrared spectroscopy (fNIRS) to assess oxygenated hemoglobin (HbO) in the prefrontal cortex during active walking and while performing a cognitive test under single- and dual-task conditions., Results: Adjusted general estimating equations models indicated that higher HbO under dual-task walking was significantly associated with a reduction in the odds of reporting falls among participants with relapsing-remitting (odds ratio (OR) = 0.472, p = 0.004, 95% confidence interval (CI) = 0.284-0.785), but not progressive (OR = 1.056, p = 0.792, 95% CI = 0.703-1.588) MS. In contrast, faster stride velocity under dual-task walking was significantly associated with a reduction in the odds of reporting falls among progressive (OR = 0.658, p = 0.004, 95% CI = 0.495-0.874), but not relapsing-remitting (OR = 0.998, p = 0.995, 95% CI = 0.523-1.905) MS., Conclusion: Findings suggest that higher prefrontal cortex activation levels during dual-task walking, which may represent compensatory reallocation of brain resources, provide protection against falls for OAMS with relapsing-remitting subtype., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: M.I. has a minor share in fNIRS device. All other authors have no conflicts of interest to report in relation to the current article. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

Guidewire-based pressure measurement is essential for diagnosing coronary artery disease. However, the impact of the guidewire on local hemodynamics and diagnostic outcomes is not fully understood. In this study, we propose a generalized reduced-order model (ROM) to accurately predict the trans-stenotic pressure drop in arteries. A key advantage of this model is that the viscous term does not rely on empirical parameters, making it applicable to both scenarios with and without guidewire insertion, and across varying stenosis severities. The proposed model demonstrates good accuracy compared to 3D idealized numerical models, achieving an average prediction error of 3.61% for cases without a guidewire and 4.53% for cases with a guidewire. Furthermore, when applied to a patient-specific model, it achieves comparable or better results than previously published ROMs. Finally, this ROM is employed to investigate the shifting relative importance of different components of the trans-stenotic pressure drop at various stenosis severities, and to provide further insights into the guidewire's influence on FFR measurements., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Neurovascular coupling links brain activity to local changes in blood flow, forming the basis for non-invasive brain mapping. Using multiscale imaging, we investigated how vascular activity spatially relates to neuronal activity elicited by single whiskers across different columns and layers of mouse cortex. Here we show that mesoscopic hemodynamic signals quantitatively reflect neuronal activity across space but are composed of a highly heterogeneous pattern of responses across individual vessel segments that is poorly predicted by local neuronal activity. Rather, this heterogeneity is dependent on vessel directionality, specifically in thalamocortical input layer 4, where capillaries respond preferentially to neuronal activity patterns along their downstream perfusion domain. Thus, capillaries fine-tune blood flow based on distant activity and encode laminar-specific activity patterns. These findings imply that vascular anatomy sets a resolution limit on functional imaging signals, where individual blood vessels inaccurately report neuronal activity in their immediate vicinity but, instead, integrate activity patterns along the vascular arbor., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Objectives: To determine if bolus administration of calcium increases pulmonary artery pressures after unifocalization procedures or pulmonary artery reconstruction surgery., Design: Retrospective cohort study using Stanford University's data warehouse., Setting: A large pediatric heart center within an academic quaternary care facility., Participants: All patients undergoing pulmonary artery reconstruction or unifocalization procedures identifiable in the data warehouse., Interventions: Data were collected from Stanford University's data repository and formatted and analyzed using RStudio (v 2023.06.1+524)., Measurements and Main Results: The primary outcome was the change in pulmonary artery systolic pressure (PASP) after a bolus administration of calcium. Secondary endpoints include changes in pulmonary arterial-to-systemic arterial pressure ratio, mean arterial pressure, right-sided filling pressure, and left atrial pressure. The Friedman test was used to assess differences and the Durbin-Conover rank-sum for pairwise comparisons. A difference in PASP after a bolus dose of calcium was found (Friedman X 2 = 13.67, p = 0.003), with a higher PASP 5 minutes after calcium administration compared with 2 minutes before administration (35 mmHg v 33 mmHg, p = 0.01), and a higher PASP 10 minutes after calcium administration compared with2 minutes before administration (35 mmHg v 33 mmHg, p = 0.008)., Conclusions: Calcium bolus administration led to an increase in pulmonary arterial pressure in patients after pulmonary artery reconstruction or unifocalization surgeries. It may be prudent to avoid bolus administration in this patient population immediately after repair or in patients with right ventricular dysfunction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The opening and closing dynamics of the aortic valve (AV) has a strong influence on haemodynamics in the aortic root, and both play a pivotal role in maintaining normal physiological functions of the valve. The aim of this study was to establish a subject-specific fluid-structure interaction (FSI) workflow capable of simulating the motion of a tricuspid healthy valve and the surrounding haemodynamics under physiologically realistic conditions. A subject-specific aortic root was reconstructed from magnetic resonance (MR) images acquired from a healthy volunteer, whilst the valve leaflets were built using a parametric model fitted to the subject-specific aortic root geometry. The material behaviour of the leaflets was described using the isotropic hyperelastic Ogden model, and subject-specific boundary conditions were derived from 4D-flow MR imaging (4D-MRI). Strongly coupled FSI simulations were performed using a finite volume-based boundary conforming method implemented in FlowVision. Our FSI model was able to simulate the opening and closing of the AV throughout the entire cardiac cycle. Comparisons of simulation results with 4D-MRI showed a good agreement in key haemodynamic parameters, with stroke volume differing by 7.5% and the maximum jet velocity differing by less than 1%. Detailed analysis of wall shear stress (WSS) on the leaflets revealed much higher WSS on the ventricular side than the aortic side and different spatial patterns amongst the three leaflets., (© 2024 The Author(s). International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.)

We studied the regulation dynamics of cerebral blood velocity (CBv) at middle cerebral arteries (MCA) in response to spontaneous changes of arterial blood pressure (ABP), termed dynamic cerebral autoregulation (dCA), and end-tidal CO 2 as proxy for blood CO 2 tension, termed dynamic vasomotor reactivity (DVR), by analyzing time-series data collected at supine rest from 36 patients with Type-2 Diabetes Mellitus (T2DM) and 22 age/sex-matched non-diabetic controls without arterial hypertension. Our analysis employed a robust dynamic modeling methodology that utilizes Principal Dynamic Modes (PDM) to estimate subject-specific dynamic transformations of spontaneous changes in ABP and end-tidal CO 2 (viewed as two "inputs") into changes of CBv at MCA measured via Transcranial Doppler ultrasound (viewed as the "output"). The quantitative results of PDM analysis indicate significant alterations in T2DM of both DVR and dCA in terms of two specific PDM contributions that rise to significance (p < 0.05). Our results further suggest that the observed DVR and dCA alterations may be due to reduction of cholinergic activity (based on previously published results from cholinergic blockade data) that may disturb the sympatho-vagal balance in T2DM. Combination of these two model-based "physio-markers" differentiated T2DM patients from controls (p = 0.0007), indicating diabetes-related alteration of cerebrovascular regulation, with possible diagnostic implications., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Abstract: Background : This study sought to predict time to patient hemodynamic stabilization during trauma resuscitations of hypotensive patient encounters using electronic medical record (EMR) data. Methods: This observational cohort study leveraged EMR data from a nine-hospital academic system composed of Level I, Level II, and nontrauma centers. Injured, hemodynamically unstable (initial systolic blood pressure, <90 mm Hg) emergency encounters from 2015 to 2020 were identified. Stabilization was defined as documented subsequent systolic blood pressure of >90 mm Hg. We predicted time to stabilization testing random forests, gradient boosting, and ensembles using patient, injury, treatment, EPIC Trauma Narrator, and hospital features from the first 4 hours of care. Results: Of 177,127 encounters, 1,347 (0.8%) arrived hemodynamically unstable; 168 (12.5%) presented to Level I trauma centers, 853 (63.3%) to Level II, and 326 (24.2%) to nontrauma centers. Of those, 747 (55.5%) were stabilized with a median of 50 min (interquartile range, 21-101 min). Stabilization was documented in 94.6% of unstable patient encounters at Level I, 57.6% at Level II, and 29.8% at nontrauma centers ( P < 0.001). Time to stabilization was predicted with a C-index of 0.80. The most predictive features were EPIC Trauma Narrator measures, documented patient arrival, provider examination, and disposition decision. In-hospital mortality was highest at Level I, 3.0% vs. 1.2% at Level II, and 0.3% at nontrauma centers ( P < 0.001). Importantly, nontrauma centers had the highest retriage rate to another acute care hospital (12.0%) compared to Level II centers (4.0%, P < 0.001). Conclusion: Time to stabilization of unstable injured patients can be predicted with EMR data., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by the Shock Society.)

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) shunts venous blood to the systemic arterial circulation to provide end-organ perfusion while increasing afterload that may impede left ventricle (LV) ejection and impair cardiac recovery. To maintain flow across the aortic valve and reduce risk of lethal clot formation, secondary mechanical circulatory support (MCS) devices are increasingly used despite limited understanding of their effects on cardiac function. This study sought to quantify the effects of VA-ECMO and combined with either intraaortic balloon pump (IABP) or percutaneous ventricular assist device (pVAD) on LV physiologic state and perfusion metrics in a porcine model of acute cardiogenic shock. Shock was induced through serial left anterior descending artery microbead embolization followed by initiation of VA-ECMO support and then placement of either IABP or pVAD. Hemodynamic measurements, LV pressure-volume loops, and carotid artery blood flow were evaluated before and after institution of combined MCS. The IABP decreased LV end-diastolic pressure by a peak of 15% while slightly increasing LV stroke work compared with decreases of more than 60% and 50% with the pVAD, respectively. The pVAD also demonstrated increased coronary perfusion and systemic pressure gradients in comparison to the IABP. Combined support with VA-ECMO and pVAD improves cardiovascular state in comparison to IABP., (Copyright © ASAIO 2024.)

Background: Exercise hemodynamics are recommended for early detection of pulmonary arterial hypertension (PAH) and have been suggested to be predictive of future development of PAH in high-risk populations such as BMPR2 mutation carriers. However, the optimal exercise hemodynamic screening parameter remains to be determined. Recent data suggest that pulmonary vascular distensibility (α) may serve as a useful parameter for early detection of PAH., Research Question: What is the value of exercise hemodynamics, including α, for predicting the occurrence of PAH during long-term follow-up in BMPR2 mutation carriers?, Study Design and Methods: Fifty-two asymptomatic BMPR2 mutation carriers who underwent symptom-limited exercise hemodynamic assessment were followed up for a median of 10 years. The impact of hemodynamics at rest and exercise, presence of exercise pulmonary hypertension, and α on occurrence of PAH during long-term follow-up were assessed., Results: During long-term follow-up, five patients developed PAH. Patients who developed PAH showed a significantly lower α (0.8 ± 0.4%/mm Hg) than patients without PAH (1.8 ± 0.8%/mm Hg; P = .008). The only hemodynamic parameter that predicted the occurrence of PAH during long-term follow-up at regression analysis was α. Receiver operating characteristic analysis showed that α ≤ 1.5%/mm Hg predicted PAH occurrence with a specificity of 75% and sensitivity of 100%., Interpretation: The results of this study indicate that before development of PAH in BMPR2 mutation carriers, α is reduced markedly and may serve as a useful parameter in the setting of early disease detection. Given the low event rate, caution is warranted in interpreting these results, highlighting the need for validation studies., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: C. G. has received compensation for scientific symposia from AstraZeneca, AOPHealth, Cordis, Janssen, and MSD; speaker fees from AOPHealth, AstraZeneca, Janssen, and Ferrer; and an educational grant from OrphaCare. A. Beurnier has received speaker fees from AstraZeneca and Sanofi Aventis. X. J. has received speaker fees from Janssen and MSD and research grants from Acceleron, Bayer, Janssen, and MSD. E. M. T. L. has received speaker fees from Janssen and GlaxoSmithKline and research grants from Janssen and has served as an advisory board member for Janssen. M. J. has received speaker fees from Janssen. A. Boucly has received compensation for scientific symposia from Janssen and MSD, speaker fees from Janssen, MSD, AOPHealth and Ferrer, and research grants from Acceleron, Janssen and MSD. H. J. B. has received speaker fees and research grants from Janssen, MSD, and Ferrer and consultancy fees from Novartis and was supported by the Dutch Cardiovascular Alliance [Grant 01-001-2017-B010, DOLPHIN-GENESIS]. G. S. has received speaker and consultancy fees from Janssen, Bayer, GlaxoSmithKline, MSD, and Pfizer and research grants from Janssen and has served as a steering committee member for Janssen. O. S. has received speaker fees from AOPHealth, Janssen, Ferrer, and MSD; consultancy fees from Acceleron, Altavant, AOPHealth, Ferrer, Gossamer Bio, Janssen, and MSD; and research grants from Acceleron, AOPHealth, Janssen, and MSD; and has served as an advisory board member for Altavant, Gossamer Bio, Janssen, and MSD. L. S. has received compensation for scientific symposia from Janssen and MSD and speaker fees from Janssen and has served as an advisory board member for Janssen. M. H. has received speaker fees from Janssen and MSD; consultancy fees from Acceleron, Aerovate, Altavant, AOPHealth, Bayer, Chiesi, Ferrer, Janssen, MSD, MorphogenIX, Shou Ti, Tiakis, and United Therapeutics; and research grants from Acceleron, AOPHealth, Janssen, MSD, and Shou Ti; and has served as an advisory board member for Acceleron, Altavant, Janssen, MSD, and United Therapeutics. D. M. has received speaker fees from Bayer, Janssen, and MSD; consultancy fees from Acceleron, Janssen, and MSD; and research grants from Acceleron, Janssen, and MSD. None declared (P. H., B. G., S. G., A. Bouchachi, D. C.)., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Aneurysms are bulges of an artery, which require clinical management solutions. Due to the inherent advantages, endovascular coil filling is emerging as the treatment of choice for intracranial aneurysms (IAs). However, after successful treatment of coil embolization, there is a serious risk of recurrence. It is well known that optimal packing density will enhance treatment outcomes. The main objective of endovascular coil embolization is to achieve flow stasis by enabling significant reduction in intra-aneurysmal flow and facilitate thrombus formation. The present study numerically investigates the effect of framing coil orientation on intra-aneurysmal hemodynamics. For the purpose of analysis, actual shape of the embolic coil is used, instead of simplified ideal coil shape. Typically used details of the framing coil are resolved for the analysis. However, region above the framing coil is assumed to be filled with a porous medium. Present simulations have shown that orientation of the framing coil loop (FCL) greatly influences the intra-aneurysmal hemodynamics. The FCLs which were placed parallel to the outlets of basilar tip aneurysm (Coil A) were found to reduce intra-aneurysmal flow velocity that facilitates thrombus formation. Involving the coil for the region is modeled using a porous medium model with a packing density of 20 % . The simulations indicate that the framing coil loop (FCL) has a significant influence on the overall outcome., (© 2024. International Federation for Medical and Biological Engineering.)

Quantification of invasive hemodynamics and mitral annular calcification-related mitral stenosis remains underexplored in patients exposed to chest radiation. We sought to explore invasive hemodynamic parameters via transseptal catheterization in patients with and without chest radiation who had a diagnosis of mitral annular calcification-related mitral stenosis. After excluding patients with more than moderate mitral regurgitation, we found that there was no difference in mitral valve area on hemodynamic testing in patients with and without radiation with an elevated baseline transmitral gradient on transthoracic echocardiography in the setting of mitral annular calcification-related mitral stenosis. There was a higher transmitral gradient and left atrial pressure in patients with prior radiation consistent with left atrial noncompliance, suggesting that treatment mitral valve stenosis may not relieve symptoms in this cohort of patients.

Background: The Resection And Partial Liver Transplantation with Delayed total hepatectomy (RAPID) procedure involves left hepatectomy with orthotopic implantation of a left lobe and right portal vein ligation. This technique induces volumetric graft increase, allowing for a right completion hepatectomy within 15 days. Notably, there is a lack of data on the hemodynamics of small-for-size grafts exposed to portal overflow without triggering small-for-size syndrome., Methods: A prospective single-center protocol included 8 living donors and 8 RAPID noncirrhotic recipients. Comprehensive clinical and biological data were collected, accompanied by intraoperative arterial and portal flow and pressure measurements. Early kinetic growth rate (eKGR%) and graft function were assessed using computed tomography and 99Tc-mebrofenin scintigraphy on postoperative days 7 and 14. Findings were compared with retrospective data from 13 left living donor liver transplantation (LDLT) recipients., Results: The median Graft-body weight ratio was 0.41% (interquartile range: 0.34-0.49), markedly lower than in LDLT. However, there was no significant difference in eKGR between RAPID and LDLT grafts. Sequential analysis revealed variable eKGR per day: 10.6% (7.8-13.2) in the first week and 7.6% (6-9.1) in the second week posttransplantation. Indexed portal flow (indexed portal vein flow) was significantly higher in RAPID compared with left LDLT ( P = 0.01). No hemodynamic parameters were found to correlate with regeneration speed. We modulated portal flow in 2 out of 8 cases., Conclusions: This study presents the first report of hemodynamic and volumetric data for the RAPID technique. Despite initial graft volumes falling below conventional LDLT recommendations, the study highlights acceptable clinical outcomes., Competing Interests: L.C. was supported by a grant from the Fondation Saint Luc. The remaining authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Pulmonary hypertension (pH) is a well-known complication among patients with chronic kidney disease (CKD). Arteriovenous fistulae (AVF) have been associated with pH mainly by increasing cardiac output. However, the burden of precapillary pH in individuals with CKD and an AVF is unclear., Objectives: To better and more fully understand the mechanism and development of precapillary pH in patients with AVF, as well as the consequences of precapillary pH in these patients., Methods: This was a large retrospective study of patients with CKD stage 4 or 5 who underwent right heart catheterization (RHC) from 2018 to 2023. The data were stratified according to the presence of AVF. To determine if AVF was independently associated with precapillary pH, we used a multivariable logistic regression analysis adjusting for demographics and potential comorbidities associated with precapillary pH, including diagnosis of chronic lung disease, obstructive sleep apnea, connective tissue disease, history of venous thromboembolism, chronic anemia, and heart failure., Results: Of 651 patients with CKD4 or CKD5, 145 (22 %) had AVF and 506 (78 %) did not have AVF. Within the AVF group, the median age was 64 years (IQR 54-71), and they were predominantly males (61 %, n = 88) and African American (77 %, n = 111). A total of 31 % (n = 45) had evidence of precapillary pH, 30 % (n = 43) of combined pH, and 14 % (n = 20) of isolated postcapillary pH. Compared to the non-AVF group, precapillary pH was more likely in the AVF group (31% vs 17 %, p < 0.0001). On multivariable analysis, AVF was independently associated with precapillary pH (OR 2.47, CI 1.56-3.89; p < 0.0001). The median time from dialysis initiation to RHC date (and precapillary pH diagnosis) was 6 years (IQR 3-8)., Conclusion: Based on RHC findings, almost one-third of patients with CKD and AVF had precapillary pH. The presence of AVF was independently associated with precapillary pH., Competing Interests: Declaration of competing interest The authors have no competing interest to disclose. None declared., (Copyright © 2024. Published by Elsevier Inc.)

Pregnancy in patients with Fontan physiology presents unique challenges due to altered cardiovascular dynamics inherent to both conditions. The Fontan procedure reroutes venous blood directly to the pulmonary arteries, bypassing the heart, and necessitating precise regulation of pulmonary venous resistance and systemic venous pressure to maintain effective cardiac output. The significant cardiovascular adaptations required during pregnancy to meet the metabolic demands of the mother and fetus can overburden the limited preload capacity and venous compliance in Fontan patients, predisposing them to a spectrum of potential complications, including arrhythmias, heart failure, thromboembolism, and obstetric and fetal risks. This review delineates the essential physiological adaptations during pregnancy and the challenges faced by Fontan patients, advocating for a comprehensive care approach involving multidisciplinary collaboration, vigilant monitoring, tailored anesthetic management, and postpartum care. Understanding the complex dynamics between Fontan physiology and pregnancy is crucial for anesthesiologists to develop and execute individualized management strategies to minimize risks and optimize outcomes for this high-risk population., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Invasive cardiopulmonary exercise testing (iCPET) combines traditional cardiopulmonary exercise testing with invasive hemodynamic measurements to assess exercise intolerance, which can be caused by preload insufficiency (PI), characterized by low ventricular filling pressures and reduced cardiac output during exertion. We hypothesize that plasma catecholamine levels at rest and during exercise correlate with hemodynamic parameters in PI., Methods: We included adult patients who underwent iCPET for exercise intolerance and had plasma catecholamines measured at rest and peak exercise., Results: Among 84 patients, PI was identified in 57 (67.8 %). Compared to patients without PI, those with PI were younger [median (IQR) 37 (28, 46) vs 47 (39,55) years, p = 0.005] and had lower workload at peak exercise [81 (66, 96) vs 95 (83.5, 110.50) Watts, p = 0.006]. Patients with PI had higher heart rates at rest and peak exercise [87 (78, 97) vs 79 (74, 87) bpm, p = 0.04; and 167 (154, 183) vs 156 (136, 168) bpm, p = 0.01, respectively]. In all patients, epinephrine and norepinephrine at peak exercise directly correlated with peak workload (r:0.41, p < 0.001 and r:0.47, p < 0.001, respectively). Resting epinephrine was higher in patients with PI [136 (60, 210) vs 77 (41, 110) pg/mL, p = 0.02]. There was no significant difference in the change in catecholamines from rest to peak exercise between patients with or without PI., Conclusion: PI patients exhibited elevated heart rate and epinephrine at rest, indicating increased sympathetic activity. We did not find strong associations between catecholamines and cardiac filling pressures, suggesting that catecholamine levels are predominantly influenced by peak workload., Competing Interests: Declaration of competing interest The authors have no significant conflicts of interest with any companies or organizations whose products or services may be discussed in this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Cardiogenic shock (CS) occurs infrequently in pregnancy and has a high mortality rate. Medical treatment options are few, with limited evidence of efficacy. Temporary mechanical circulatory supports (tMCS) may play a key role in addressing this therapeutic lacuna. We report successfully managing second-trimester CS using an Impella 5.5 micro-axial pump. Our patient presented in the second-trimester with CS. Hemodynamic parameters indicated biventricular dysfunction (low cardiac index, low pulmonary artery pulsatility index). She received diuresis and inotropic support to optimize her fluid status and cardiac function. However, failure to improve to the point where she would be able to tolerate the hemodynamic stresses of labor despite optimizing medical therapy prompted consideration of tMCS. The Impella 5.5 was chosen for its higher output (to maximize fetal perfusion), relative longevity, and lower hemolysis rates compared to other devices. It was used to support her from gestational weeks 28-30 and through the delivery. Support was continued for 4 weeks postpartum to allow for any potential cardiac recovery. Hope unrealized, a workup for destination therapy was initiated. Patient preference and high panel reactive antibodies informed the decision to pursue destination left ventricular assist device (LVAD) therapy. After a 3 month neonatal intensive care unit (NICU) stay, mother and baby were successfully discharged home., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2024.)

The present investigation aimed to study the cardiovascular responses and the cerebral oxygenation (Cox) during exercise in acute hypoxia and with contemporary mental stress. Fifteen physically active, healthy males (age 29.0 ± 5.9 years) completed a cardiopulmonary test on a cycle ergometer to determine the workload at their gas exchange threshold (GET). On a separate day, participants performed two randomly assigned exercise tests pedaling for 6 min at a workload corresponding to 80% of the GET: (1) during normoxia (NORMO), and (2) during acute, normobaric hypoxia at 13.5% inspired oxygen (HYPO). During the last 3 min of the exercise, they also performed a mental task (MT). Hemodynamics were assessed with impedance cardiography, and peripheral arterial oxygen saturation and Cox were continuously measured by near-infrared spectroscopy. The main results were that both in NORMO and HYPO conditions, the MT caused a significant increase in the heart rate and ventricular filling rate. Moreover, MT significantly reduced (74.8 ± 5.5 vs. 62.0 ± 5.2 A.U.) Cox, while the reaction time (RT) increased (813.3 ± 110.2 vs. 868.2 ± 118.1 ms) during the HYPO test without affecting the correctness of the answers. We conclude that in young, healthy males, adding an MT during mild intensity exercise in both normoxia and acute moderate (normobaric) hypoxia induces a similar hemodynamic response. However, MT and exercise in HYPO cause a decrease in Cox and an impairment in RT., Competing Interests: The authors have no conflicts of interest that are directly relevant to the content of this manuscript.