Search Results (937)

This work focuses on the development of a patient-specific transient CFD–FSI numerical model combined with the Time-Averaged Entropy Generation Rate (TAEGR) to predict hemodynamic parameters in the thoracic aorta, including the Oscillatory Shear Index (OSI) and the Time-Averaged Wall Shear Stress (TAWSS). While arterial blood flow can be modeled assuming either rigid or elastic arterial walls, the effect of wall compliance on these parameters, particularly on TAEGR, remains insufficiently characterized. Moreover, the interpretation of established indicators is not unique, as regions of vascular relevance may correspond to either high or low values of OSI and TAWSS. The proposed approach aims to identify symmetry and asymmetry in shear stress and entropy generation within the arterial wall, which are closely associated with the development of atherosclerotic plaque. Four aortas from clinical patients were analyzed using the proposed numerical framework to investigate blood flow behavior. The results revealed regions with high values of the hemodynamic parameters (OSI > 0.15, TAWSS ≥ 2 Pa, and TAEGR ≥ 20 $\mathrm{W}/{\mathrm{m}}^3\mathrm{K}$) predominantly located in the vicinity of the upper arterial branches. These regions, referred to as critical zones, are considered prone to the development of cardiovascular diseases, particularly atherosclerosis. The proposed numerical model provides a reliable qualitative framework for assessing symmetry and asymmetry in aortic blood flow patterns under different surgical conditions. Full article

Background/Objectives: Despite the widespread recognition of preprocedural anxiety in awake invasive procedures, there is a paucity of data examining its prevalence and clinical impact in patients undergoing percutaneous kidney biopsy. This study aimed to determine the prevalence of preprocedural anxiety, assess its association with peri-procedural hemodynamic parameters, and identify factors associated with elevated anxiety. Methods: In this prospective observational study, 151 adults scheduled for percutaneous kidney biopsy between June 2023 and January 2025 were enrolled. Anxiety was assessed 24 h before the procedure using the Thai State–Trait Anxiety Inventory Y1 (STAI-Y1). Blood pressure and pulse rate were measured at baseline and 30 min before biopsy. Mixed-effects models evaluated associations between anxiety and hemodynamic changes, and logistic regression identified predictors of anxiety. Results: Clinically significant anxiety (STAI-Y1 ≥ 40) was present in 55% of patients, with 43.4% reporting very high anxiety. Anxiety status was not independently associated with changes in systolic or diastolic blood pressure or pulse rate. However, diastolic blood pressure increased significantly from baseline to preprocedural across all patients (mean increase 5.45 mmHg; p = 0.008), irrespective of anxiety. Higher serum creatinine (OR 1.29; p = 0.012) and a history of previous kidney biopsy (OR 4.28; p = 0.004) were independently associated with anxiety. Conclusions: Preprocedural anxiety is highly prevalent among patients undergoing kidney biopsy but does not independently influence peri-procedural hemodynamic parameters. Targeted screening and supportive interventions may benefit patients at increased risk of anxiety. Full article

Doppler assessment of fetal cerebral circulation has become a cornerstone of modern fetal medicine. It is used to evaluate cerebral vascular malformations, brain anomalies, fetal growth restriction due to placental insufficiency, fetal anemia, and hemodynamic complications arising from placental vascular anastomoses in monochorionic pregnancies. Emerging research also explores the predictive value of Doppler parameters for perinatal outcomes and long-term neurodevelopment. To review the anatomy and physiology of fetal cerebral vessels accessible to Doppler evaluation, outline key technical aspects, and summarize current obstetric applications. A PubMed search identified 113 relevant publications, published between 1984 and 2025. Three book chapters by authors recognized internationally within the scientific community were included. A total of 116 publications were critically analyzed in this narrative review. Strong evidence supports the use of Doppler ultrasound in obstetrics, particularly for evaluating fetal cerebral hemodynamics, where it contributes to reducing fetal morbidity and mortality. Doppler assessment of fetal brain circulation is a valuable tool for evaluating brain vascular malformations, other structural abnormalities, and for assessing fetuses with growth restriction, anemia, and twin-to-twin transfusion syndrome. It allows targeted fetal monitoring and timely interventions, providing critical prognostic information and aiding parental counseling. Ongoing advances in Doppler technology and understanding of fetal brain physiology are likely to broaden its clinical uses, improving both perinatal outcomes and long-term neurological health. Full article

Background/Objectives: Flexible bronchoscopy (FB) enables airway exploration and diagnosis of various respiratory pathologies, but the sedation and instrumentation required during the procedure raise oxygen demand while reducing ventilation, which can lead to hypoxemia. Conventional oxygen therapy (COT) may not adequately prevent desaturations in high-risk groups, as patients with moderate respiratory deficiency. High-flow nasal cannula (HFNC) can deliver heated, humidified oxygen at high flow rates, generating low-level positive airway pressure, improving oxygenation, reducing dead-space, and enhancing procedure tolerance. Prior studies have shown that HFNC can improve gas exchange and reduce desaturations during bronchoscopy. However, evidence remains limited for patients with moderate respiratory deficiency, who are particularly vulnerable. Evaluating the feasibility and safety of HFNC in this population is essential to guide safe procedural practice. Methods: A retrospective observational study including patients undergoing FB with HFNC support between January and May 2025. Inclusion criteria were BMI between 18 and 30; age > 18 years old; moderate respiratory dysfunction, defined by pulse oximetry, Pulmonary Functional Tests (PFTs) and Arterial Blood Gas (ABG) analysis. Exclusion criteria were intolerance/contraindication to HFNC. Procedures were performed under basic monitoring. Primary outcome was occurrence of severe hypoxemia (SpO2 < 90%). Secondary outcomes were needed for rescue maneuvers, interruption for conversion to other ventilatory strategies, and hemodynamic instability. Results: No severe desaturations were recorded, all procedures were completed without rescue maneuvers or other ventilatory strategies, and no hypoxemia occurred. Mean duration of the procedure was 9 min. Vital parameters were maintained within the normal ranges, with a mean SpO₂ during bronchoscopy of 98%. Conclusions: HFNC enables oxygenation and ventilation without adverse events in sedations for FB in patients with moderate respiratory deficiency. Full article

Background: Ventricular function assessments in Fontan patients remain challenging. Ejection fraction (EF) lacks sensitivity for early dysfunction, and the roles of strain and advanced imaging in systemic left ventricle (LV) physiology are not fully defined. We aimed to compare (i) LV and atrial strain indices between pediatric Fontan patients with preserved EF (P-LVEF) versus reduced EF (R-LVEF) and (ii) echocardiographic global longitudinal strain, segmental longitudinal strain indices, and conventional 2D and 3D echocardiographic parameters through cardiac morphology. Methods: Pediatric patients with Fontan circulation and systemic LV morphology underwent clinical, hemodynamic, and multimodality echocardiographic evaluation, including 2D/3D parameters, global and segmental LV strain, and left atrial strain. Outcomes were analyzed according to EF status and congenital morphology. Significant results from multiple comparisons were followed by post hoc analysis, where appropriate. Results: Patients with a reduced EF exhibited a worse clinical status, a higher pulmonary vascular resistance index, and greater systemic congestion compared with those with a preserved EF. Conventional 2D indices showed no significant differences between the two studied groups except for LV end-systolic volume (ESV) (p = 0.0315) and LV end-systolic longitudinal diameter (ESL) (p = 0.0024), which showed higher values in the R-LVEF group. Although the relative frequency of impaired deformation was higher in Fontan patients with an unbalanced atrioventricular canal compared with the Fontan patients with a tricuspid atresia + pulmonary stenosis + ventricular septal defect, the difference did not reach statistical significance (p = 0.1365). Most segmental longitudinal strain values were not significantly different across patients with different cardiac morphology, except for the basal anterior segment and apical inferoseptal segment (p < 0.05). Conclusions: In pediatric Fontan patients with systemic LV morphology, a reduced EF was associated with a worse clinical and hemodynamic status. Conventional echocardiographic indices showed a limited ability to differentiate between the compared groups. Although no statistically significant differences were detected between pediatric Fontan patients with preserved EF and reduced EF, LV and atrial strain indices provided complementary information on ventricular–atrial interactions and myocardial deformation. These findings are exploratory and warrant confirmation in larger, prospective studies. Full article

Background: Left lateral tilt is traditionally recommended during cesarean delivery to reduce aortocaval compression and maintain maternal hemodynamic stability; however, with the widespread adoption of prophylactic vasopressor strategies recommended by current guidelines, the incremental benefit of routine tilt remains uncertain. Methods: We conducted a prospective, nonrandomized observational comparative study at the University Hospital Bratislava including 99 women undergoing elective cesarean delivery under spinal anesthesia. Participants were managed either with a standard ~15° left lateral tilt (n = 41) or in a flat supine position without tilt (n = 58), according to the day of surgery and routine anesthesiologist practice; all other anesthetic and surgical procedures were identical. A prophylactic norepinephrine infusion was initiated at 0.05 µg/kg/min and titrated to maintain systolic arterial pressure at 90–100% of baseline. The primary outcome was the average norepinephrine infusion rate (µg/kg/min) from induction of spinal anesthesia to neonatal delivery. Secondary outcomes included total norepinephrine dose to delivery, dose normalized per kilogram, and neonatal outcomes (Apgar scores and umbilical arterial blood gas parameters). Results: The median norepinephrine infusion rate was 0.03 µg/kg/min in both groups (tilt: IQR 0.01–0.04 vs. no-tilt: IQR 0.02–0.04; p = 0.325). Total norepinephrine dose to delivery (20 [15–35] µg; p = 0.89) and dose per kilogram (0.25 [0.15–0.33] µg/kg vs. 0.34 [0.17–0.44] µg/kg; p = 0.10) were also comparable. Neonatal outcomes, including Apgar scores and umbilical arterial blood gas parameters, did not differ significantly between groups. In a multivariable regression sensitivity analysis adjusting for maternal and procedural covariates, table tilt was not independently associated with norepinephrine requirements. Conclusions: In parturients undergoing cesarean delivery under spinal anesthesia with prophylactic norepinephrine infusion, a 15° left lateral tilt did not reduce vasopressor requirements or improve neonatal outcomes. Routine maternal tilt therefore appears unnecessary for hemodynamic optimization in this setting, and patient positioning can be individualized without compromising maternal or neonatal safety. Full article

Background: The no-reflow phenomenon remains a frequent and clinically significant complication in patients with ST-segment elevation myocardial infarction (STEMI) despite advances in primary percutaneous coronary intervention (pPCI). Its determinants are multifactorial and not fully established. This study aimed to identify independent predictors of impaired reperfusion after pPCI. Methods: In this prospective study, 100 consecutive STEMI patients treated with successful pPCI in a high-volume tertiary center were analyzed. Impaired reperfusion was defined as ST-segment resolution < 50% or final TIMI flow < 3. Clinical characteristics, laboratory findings, including platelet reactivity, and detailed angiographic and procedural parameters were collected. Independent predictors were evaluated using multivariable logistic regression. Thirty-day and twelve-month mortality were assessed with Kaplan–Meier analysis. Results: Impaired reperfusion occurred in 39% of patients. Compared with the normal reperfusion group, patients with noreflow were older, had lower left ventricular ejection fraction, eGFR, longer ischemia times, and more often presented with anterior STEMI. Platelet reactivity did not differ between groups. Four variables independently predicted impaired reperfusion: longer pain-to-balloon time (OR 1.05 per 10 min, 95% CI 1.02–1.07; p < 0.001), anterior myocardial infarction (OR 5.05, 95% CI 1.14–22.38; p = 0.03), use of predilatation (OR 7.66, 95% CI 1.78–32.9; p = 0.006), and higher Killip–Kimball class (OR 7.69, 95% CI 1.88–31.38; p = 0.004). Impaired reperfusion was associated with significantly higher mortality at 30 days (1.6% vs. 10%; p < 0.001) and 12 months (3.2% vs. 25.6%; p < 0.001). Conclusions: In this prospective STEMI cohort, impaired reperfusion was frequent and strongly associated with adverse short- and long-term outcomes. Ischemia duration, infarct location, hemodynamic status, and procedural strategy were key determinants of noreflow, while platelet reactivity showed no significant association. Full article

Background/Objectives: The diagnosis and risk stratification of valvular heart disease have traditionally relied on resting echocardiography. However, in a significant portion of patients, resting findings do not fully reflect the hemodynamic severity of the condition, particularly in asymptomatic individuals with severe valvular disease or those with nonspecific symptoms. In this context, stress echocardiography emerges as a vital imaging modality, providing a dynamic assessment of valvular, ventricular, and pulmonary function under hemodynamic load (from physical exercise or pharmacological agents). Methods: We conducted a comprehensive synthesis and critical evaluation of the current landscape, recent advancements, and future directions regarding the application of stress echocardiography in valvular heart disease. Results: This comprehensive review explores the incremental role of stress echocardiography in valvular heart disease, analyzing the evolution of its clinical applications, from low-flow, low-gradient aortic stenosis to the evaluation of contractile reserve and exercise-induced pulmonary hypertension in mitral stenosis and regurgitation. We discuss standardized protocols, key parameters to monitor, and the diagnostic and prognostic outcomes from major clinical trials and current guidelines. Attention is given to stress echocardiography’s ability to unmask the true severity of the disease and to identify patients at high risk for adverse events, thereby guiding crucial clinical decisions, such as the optimal timing for surgical or transcatheter intervention. Conclusions: The review evaluates the limitations of modality and outlines future research directions, including its integration with new technologies like 3D echocardiography and speckle tracking techniques, to further optimize the role of stress echocardiography as a decision-making tool in the multidisciplinary management of valvular heart disease. Full article

Coarctation of the aorta is a localized narrowing of the aortic lumen. This pathology leads to hypertension in upper extremity vessels, left ventricular hypertrophy and to impaired perfusion of the abdominal cavity and lower extremities. Along with traditional diagnostic methods, mathematical modeling is used for risk assessment and the prediction of disease outcomes. However, when applying numerical models to describe hemodynamic parameters, the choice of turbulence model to describe swirling flow occurring in the aorta in this pathology must be justified. Thus, three turbulence models, namely k-ε, k-ω, and SST were analyzed for the description of swirling flows in the study of coarctation’s effect on hemodynamic parameters and analysis of the mechanisms leading to various cardiovascular diseases caused by altered hemodynamics. The results revealed significant differences in swirling flow patterns between the k-ε and k-ω models, while the k-ω and SST models showed consistent results over the cardiac cycle. In the peak systolic phase, average velocity rises to 1.07–1.98 m·s⁻¹ for the k-ε model, 0.82–2.12 m·s⁻¹ for the k-ω model, 1.22–2.12 m·s⁻¹ for the SST model and 0.8–2.12 m·s⁻¹ for laminar flow. WSS values increase rapidly to 11–22 Pa in k-ε, 25–50 Pa in k-ω and SST models of turbulence, and 30–55 Pa for laminar flow. Significant differences were also evident in the prediction of wall shear stress, with the k-ε model giving values more than twice as high as the k-ω and SST models. The data obtained confirm the necessity of careful model selection for accurate hemodynamic parameter estimation, especially in coarctation. The findings of this study can be used for further physics-informed neural network analysis of evaluation of treatment evaluations for congenital heart disease patients. Full article

Background and Objectives: The use of the HeartMate 3 (HM3) ventricular assist device (VAD) as a bridge to transplant is rising notably in pediatric patients with end-stage heart disease. This study reports a single-centre experience with the HM3 device in pediatric patients. Materials and Methods: We conducted a retrospective clinical data review (including procedural, perioperative and follow-up parameters) of pediatric patients (n = 5, aged 10–16 years) supported with HM3 VAD at our institution between January 2022 and October 2025. Results: During this period, five pediatric patients (median age of 13 years [range 10–16, IQR 10–14.5]; median weight of 41.5 kg [24–75 IQR 32–62]) underwent HM 3 implantation. The Pedimacs profiles ranged from 1 to 2. Two patients with Pedimacs profile 1 received a temporary left ventricular assist device preoperatively for hemodynamic stabilization. The median intensive care unit stay was 47 days (range 21–54, IQR 28–50.5). Right ventricular dysfunction occurred in four patients and was managed conservatively in three, while one required intraoperative implantation of a temporary CentriMag right ventricular assist device. Two patients remain on device support, while three patients were successfully bridged to heart transplantation. No mortality was observed, and none of the patients experienced pump-related complications. Conclusions: The use of the HeartMate 3 is a safe and effective treatment strategy for successful bridging to heart transplantation. Right ventricular dysfunction is a common and clinically significant complication, but it can be effectively managed with appropriate measures. Full article

Background: Mock circulatory loops (MCLs) are benchtop experimental platforms that reproduce key features of the human cardiovascular system, providing a safe, controlled, and reproducible environment for haemodynamic investigation. This scoping review aims to systematically map the current landscape of MCLs used for aortic simulation and identify major areas of application. Methods: A systematic search of PubMed, Scopus, and Web of Science identified original studies employing MCLs for aortic simulation. Eligible studies were categorized into predefined themes: (I) (bio)mechanical aortic characterization, (II) hemodynamics, (III) device testing, (IV) diagnostics, and (V) training. Data on MCL configurations, aortic models, and study objectives were synthesized narratively. Results: Eighty-four studies met the inclusion criteria. Twenty-five investigated aortic biomechanics, 23 hemodynamics, 22 device or product testing, 13 validated diagnostic imaging techniques, and one training application. Models included porcine (n = 22), human cadaveric (n = 7), canine (n = 1), ovine (n = 1), bovine (n = 1), and 3D-printed or molded aortic phantoms (n = 55). MCLs were employed to study parameters such as aortic stiffness, flow dynamics, dissection propagation, endoleaks, imaging accuracy, and device performance. Conclusions: This review provides a comprehensive overview of MCL applications in aortic research. MCLs represent a versatile pre-clinical platform for studying aortic pathophysiology and testing endovascular therapies under controlled conditions. Standardized reporting frameworks are now required to improve reproducibility and accelerate translation to patient-specific planning. Full article

Background/Objectives: Spinal anesthesia (SA) for cesarean section and epidural analgesia (EA) for vaginal delivery induce hemodynamic changes that may compromise maternal and fetal safety. In this observational, hypothesis-generating study, we used impedance cardiography (ICG) to characterize maternal hemodynamic responses to EA for labor versus SA for cesarean delivery and to describe hemodynamic profiles associated with commonly used local anesthetic and vasopressor regimens. Methods: In this observational study, 132 women at term were included (52 with epidural analgesia (EA), 80 with spinal anesthesia (SA)). Hemodynamic parameters were measured using the ICON electrical cardiometry monitor (Osypka Medical GmbH). ICON and oscillometric blood pressure (BP) monitoring captured cardiac index (CI), stroke volume (SV), heart rate (HR), systemic vascular resistance index (SVRI), and thoracic fluid content (TFC) at T0 (baseline), approximately 5 and approximately 10 min, skin incision, delivery, and oxytocin administration. Results: CI remained stable and comparable between EA and SA (3.9 ± 0.6 vs. 3.9 ± 0.6 L/min/m²; p = 0.530). SV was higher in EA (85.1 ± 11.3 vs. 78.1 ± 9.7 mL; p < 0.001), whereas HR was higher in SA (92.2 ± 12.9 vs. 85.8 ± 12.5 bpm; p = 0.009). In EA, ropivacaine and bupivacaine showed similar hemodynamic profiles. Within the SA cohort, women managed with phenylephrine infusion had lower CI and HR but higher MAP and SVRI compared with those receiving ephedrine boluses, consistent with the expected pharmacodynamic profiles of these agents. Conclusions: ICG was feasible and provided dynamic, noninvasive estimates of maternal cardiovascular adaptation during obstetric anesthesia. In this non-randomized, exploratory cohort, descriptive differences in hemodynamic profiles between vasopressor strategies were more pronounced than between local anesthetics. Phenylephrine-based management showed a pattern of higher BP and SVRI but lower CI and HR, whereas ephedrine-based management tended to preserve CI through chronotropic effects. Full article

Abdominal aortic aneurysm (AAA) is a dangerous disease and can cause sudden death if it ruptures. This study investigated blood flow behaviors and hemodynamic changes in three categories (small, medium and large diameters) of AAAs using computational fluid dynamics (CFD) based on patient geometry. Computed tomography images of patients with abdominal aortic aneurysms were used to construct a patient-specific AAA model. This study included one healthy subject and seven patients who had AAAs with a diameter larger than 3 cm. The results showed that the aortic aneurysms were highly turbulent in the diastolic phase, and there was an increase in turbulence as the aneurysm size increased. The time-averaged wall shear stress (TAWSS) in the artery was high at peak systole and decreased during diastole. The oscillating shear index (OSI) was higher at the middle and distal aortic aneurysm sac than in other areas. Low TAWSS and a high OSI in the aneurysm region may indicate a risk of wall rupture in AAA. This study suggests that CFD provides further insights by visualizing blood flow behaviors and quantitatively analyzing hemodynamic parameters. Full article

Background/Objectives: Echocardiography is the reference standard for grading aortic stenosis (AS); however, it yields discordant severity estimates in up to 40% of patients. Multidetector computed tomography (MDCT)-derived methods for calculating aortic valve area (AVA) may improve diagnostic concordance, but their diagnostic performance, validation against invasive hemodynamics, and the influence of left ventricular outflow tract (LVOT) morphology on severity grading remain insufficiently investigated. Methods: We retrospectively analyzed 307 patients with normal-flow, high-gradient calcific AS who underwent echocardiography, MDCT, and cardiac catheterization. AVA was calculated using (1) echocardiographic LVOT diameter, (2) hybrid Doppler–MDCT planimetric LVOT area, and (3) corrected echocardiographic LVOT diameter (×1.13). Agreement, correlation, and diagnostic performance were assessed using Bland–Altman analysis, Pearson correlation, ROC analysis, and McNemar’s test. Subgroups defined by diagnostic concordance and MDCT-derived LVOT size were compared using ANOVA. Results: Hybrid AVA showed a strong correlation with echocardiographic AVA (r = 0.749, p < 0.001), with a mean difference of +0.11 ± 0.15 cm². Both methods demonstrated similar relationships with invasive and non-invasive hemodynamic markers of AS severity. When combined with echocardiography, the hybrid method increased concordant classification of severe AS by 8%. In contrast, corrected AVA performed significantly worse, leading to more discordant classifications. LVOT size was significantly associated with variability in AVA and Doppler velocity index, independent of flow status. Conclusions: Hybrid MDCT-derived AVA provides diagnostic performance equivalent to echocardiography and improves concordance in selected patients. LVOT size influences key echocardiographic parameters and may warrant tailored diagnostic thresholds. Full article

Background and Objectives: Trauma remains a leading global cause of preventable mortality, and outcome prediction tools are essential for both triage and resource allocation. Timely and effective medical response to trauma patients is of the essence. While there are already some widely accepted trauma scores, our aim was to build a more precise model tailored to our cohort as a framework for future research. Materials and Methods: A retrospective cohort of 91 patients was analyzed, using several clinical and paraclinical factors to build a logistic regression model that predicted 30-day mortality. Results: After adjusting for collinearity, our final multiple regression model, comprising systolic blood pressure, glycemia, urea serum levels and number of fractures, showed an excellent model fit (McFadden R² = 0.682; AUC = 0.94) for predicting 30-day mortality. Systolic blood pressure was significantly associated with mortality (OR = 0.944, 95% CI: 0.920–0.969). In our cohort it seems to surpass the performance of The Trauma and Injury Severity Score (McFadden R² = 0.56; AUC = 0.90). Conclusions: Commonly available clinical parameters could contribute to risk stratification, highlighting the prognostic importance of hemodynamic instability and metabolic response. This study was conducted on a small cohort as an exploratory analysis. Further research and validation based on multicentric cohorts are needed. Full article