Stiffness Index Research Articles

Left atrial strain in patients without cardiovascular disease: uncovering influencing and related factors

BackgroundDespite its proven prognostic value in different contexts, the precise implications of left atrial strain (LAS) assessment throughout different phases of the atrial cycle remain uncertain. A direct correlation between left atrial reservoir strain (LARS) and left ventricular global longitudinal strain (GLS) has been consistently demonstrated in several studies involving patients with various heart diseases. The objective of our study is to identify factors directly associated with LARS, left atrial conduction strain (LACS) and left atrial booster strain (LABS) in patients without cardiovascular (CV) disease.MethodsTransthoracic echocardiographic examinations in patients without CV disease were prospectively selected in two tertiary hospitals echocardiography labs for clinical purposes. LAS, maximal and minimal left atrial (LA) volumes and left atrial ejection fraction (LAEF) were measured using the two-dimensional strain analysis package provided by the EchoPAC Plugging workstation (AFI LA).ResultsA total of 196 cases were included, median age of 54 (45–62) with 85 (43%) being men. The mean left ventricular ejection fraction (LVEF) was 61% ± 5, and the median GLS was − 18% (-17 to -20). Median indexed maximum volume of left atrium (LAVI) was 27 ml/m2 (22–31), and LAEF was 64% (58–70). The mean LARS biplane was 35,1% ± 8. Notably, LARS was greater in the 2-chamber view (36,1% ± 10) compared to the 4-chamber view (34,1% ± 8 p < 0,05). The multivariate analysis of LARS revealed that sex, GLS, LAEF and e’mean are independently correlated with LARS. Multivariate analysis of LACS showed independent correlations between LACS and age, GLS, LAEF, E/A ratio and e’mean. Conversely, the multivariate analysis of LABS demonstrated significant correlations among A wave, e’mean, and left atrial stiffness index (LASI).ConclusionsIn patients without CV disease, GLS emerges as a crucial determinant of LARS and LACS. LAEF and e’mean are directly and independently related to both LARS and LACS. LARS (univariate) and LACS (multivariate) exhibited a decline with older age in individuals without CV disease.

Effect of Controlled Expiratory Pressures on Cerebrovascular Changes During Valsalva Maneuver

This study aimed to investigate the effects of Valsalva maneuver (VM) with the controlled expiratory pressures on vascular stiffness of common carotid artery (CCA) and cerebral hemodynamic changes using diagnostic ultrasonography. Twenty-seven healthy participants (mean and standard deviation of age = 22.78 ± 1.89) performed 30 and 40 mmHg VM. The right CCA stiffness index and pulse wave velocity (PWV) were measured before (PRE) and after (POST) VM. The peak systolic velocity (PSV), resistance index (RI), and heart rate (HR) were measured before (PRE) and after (POST1 and POST2 during the first and the second 15 s, respectively) VM. Near-infrared spectroscopy (NIRS) was utilized to measure regional oxygen saturation (rSO2) and oxyhemoglobin (HbO) on the left and right prefrontal cortex. Stiffness index decreased by 1.76 (p &lt; 0.001) from PRE to POST only after 30 mmHg VM. PWV decreased by 0.69 m/s (p &lt; 0.001, 30 mmHg) and 0.34 m/s (p = 0.022, 40 mmHg) in POST. Conversely, PSV increased by 5.36 cm/s (p = 0.031, 30 mmHg) and 4.77 cm/s (p = 0.04, 40 mmHg) in POST2. Increase in RI (p = 0.017) and decrease in HR (p = 0.003) occurred only after the 40 mmHg VM. Right HbO decreased after 30 mmHg VM (p = 0.023) from PRE to POST1, and right rSO2 increased after 40 mmHg VM (p = 0.036) from VM (during) to POST1. Both 30 and 40 mmHg VM showed a significant improvement in PWV and an increase in PSV. However, at 30 mmHg VM, a significant decrease in HbO was observed after VM owing to increased cerebral oxygen exchange, and at 40 mmHg VM, an rSO2 increase was observed after VM owing to high vascular pressure. Additionally, the increased pressure and rSO2 at 40 mmHg may have been caused by increased RI. The results indicated that the 30 mmHg VM was more effective on CCA stiffness than the 40 mmHg VM.

Experimental Investigation of Tensile, Shear, and Compression Behavior of Additional Plate Damping Structures with Entangled Metallic Wire Material

To fulfill the vibration damping requirements of plate structures under complex conditions, additional damping structures with entangled metallic wire material (EMWM) are proposed based on the excellent physical properties of EMWM. A batch of specimens with different filament diameters, densities, and thicknesses are prepared. The stiffness and loss factors are taken as the evaluation indexes, and orthogonal tests are conducted to obtain the tensile, shear, and compression properties. The results show that the optimal parameter combinations can be obtained through orthogonal tests. For the specimens with optimal parameter combinations, the mechanical tests under different loading rates and loading displacements are carried out. With the increase in loading rate, the tensile and shear forces appear to display fracture failure in advance, and the compression performance is stable without significant changes. The change rule under each mechanical test is explored using the stiffness and loss factor evaluation index. It provides a reference for the analysis of the preparation parameters of subsequent additional damping structures with EMWM.

Association of Objectively Measured Sedentary Behavior With Arterial Stiffness: Findings From the Nijmegen Exercise Study.

Sedentary behavior (SB) may affect arterial stiffness, preceding the development of cardiovascular disease. We investigated the association of objectively measured SB with arterial stiffness. We also investigated factors that affected this association. We recruited adult volunteers and measured SB with thigh-worn accelerometery for 24 hrs/day for eight consecutive days. Central (carotid-femoral pulse wave velocity, cfPWV, gold standard) and local carotid arterial stiffness (stiffness index Beta and pressure-strain elasticity EP) were measured with ultrasound. Linear regression was used and adjusted for demographics, cardiometabolic factors, and moderate-to-vigorous physical activity (MVPA) volume. Effect modification was studied with interaction terms. Participants (N = 664, 64 (standard deviation: 11, range: 23-89) years, 397 (59.8%) male) demonstrated 9.1 (1.6) hrs/day of SB, and arterial stiffness was 8.6 (3.0) m/s for cfPWV, 6.4 (2.9) for Beta, and 87 (43) kPa for EP. SB was not associated with cfPWV (β = 0.04 95% CI (-0.11, 0.18), p = 0.60). The association of SB with local arterial stiffness was modified by systolic blood pressure (SBP) and MVPA volume. Stratified analyses revealed positive associations of SB with Beta (β = 0.29 (0.05, 0.53), p = 0.016) and EP (β = 4.83 (1.39, 8.27), p = 0.006) in participants with SBP > 134 mmHg or > 103 min/day of MVPA (β = 0.23 (0.03, 0.42), p = 0.024 and β = 3.55 (0.82, 6.29), p = 0.011, respectively). We found no association of objectively measured SB with central arterial stiffness. However, SB was positively associated with local carotid stiffness in participants with higher SBP or MVPA levels. In certain subgroups, SB may affect carotid arterial stiffening, reinforcing the relation between SB and cardiovascular disease.

Association between sedentary behavior and bone mass, microstructure and strength in children, adolescents and young adults: a systematic review

Sedentary behavior (SED) research is currently receiving increasing attention in the field of public health. While it has been shown to have negative effects on cardiovascular or metabolic health, there is limited knowledge regarding the relationship between SED and bone health in children, adolescents, and young adults. Thus, the purpose of this review is to investigate the associations between SED and bone health status, specifically bone mass, microstructure, and strength. A comprehensive literature search was conducted across five electronic databases, including EMBASE, PubMed, Medline, Cochrane, Web of Science and CNKI. The inclusion criteria were as follows: healthy participants aged 24 years or younger, with measured SED and measured bone outcomes. The quality of the included articles was assessed using the National Institute of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. After excluding, the final sample included 25 cross-sectional, 9 observational and 2 both cross-sectional and longitudinal studies. Among these, seven were rated as ‘high quality’, twenty-three were rated as ‘moderated quality’, and six were rated as ‘low quality’ according to the quality assessment criteria. After summarizing the evidence, we found no strong evidence to support an association between BMC or BMD and SED, even when considering gender or adjusting for moderate-to-vigorous physical activity (MVPA). However, a strong level of evidence was found indicating a negative relationship between objectively measured SED and cortical bone mineral density (Ct.BMD) in the tibia or stiffness index (SI) in the Calcaneus across all age groups. While the association between adverse bone health outcomes and SED still cannot be confirmed due to insufficient evidence, these findings suggest that bone microstructure and strength may be more sensitive to SED than bone mass. Thus, further evidence is needed to fully understand the connection between sedentary behavior and bone health, particularly regarding the relationship between SED and bone strength.

Echocardiographic left atrial stiffness index predicts high left ventricular filling pressures in patients with acute heart failure: an observational study.

In acute heart failure (AHF) patients, non-invasive estimation of left ventricular filling pressures (LVFPs) appears crucial to guide management. Although poorly investigated, left atrial (LA) mechanics play a pivotal role in this setting. This report sought to assess the correlation of echocardiographic LA stiffness index with invasive LVFPs and its diagnostic accuracy as compared to other parameters used in clinical practice. In this observational, prospective study, 104 patients with suspected acute coronary syndrome and signs/symptoms of AHF were enrolled. Available invasive estimation of LVFPs was required. Comprehensive echocardiography was performed for all patients, including LA reservoir strain (LARS). LA stiffness index was derived by speckle-tracking analysis and Tissue Doppler imaging as early diastolic transmitral inflow velocity/mitral annulus early diastolic velocity [E/e']/LARS. Invasively measured LVFPs showed a strong correlation with LA stiffness index (Spearman ρ = 0.773, p < 0.0001), as well as with LARS and E/e'. Receiver operating characteristic (ROC) curve analysis was used to demonstrate better accuracy performed by LA stiffness index than average E/e', LA volume or LARS alone, in predicting high LVFPs. Guideline-recommended assessment of diastolic function was finally compared to LARS and LA stiffness index performances in an independent population group; we were hence able to obtain a LA stiffness threshold of 0.48 with a positive predictive value of 91.7% and a negative predictive value of 88.9% in identifying patients with high LVFPs. For the first time, diagnostic performance of LA stiffness index has been investigated in a heterogeneous AHF population, providing correlations with invasively measured LVFPs and comparisons with established diastolic function metrics.

Early left atrial changes in patients with systemic sclerosis by two-dimensional speckle tracking echocardiography

Abstract Background Systemic Sclerosis (SSc) is an autoimmune disease that affects multiple organs 1. Primary myocardial involvement is not uncommon in SSc, with poor prognosis when symptomatic2-4. Pulmonary hypertension and right-sided affection of the heart are well-studied in SSC. Changes in the function of the left atrium (LA) in patients with SSc are early signs of left-sided affection of the heart, which has not yet been well investigated. Two-dimensional (2D) speckle tracking echocardiography (STE) is useful for detecting these early changes. Aim To assess the LA strain parameters in patients with SSC by 2D STE compared to age and sex-matched healthy subjects. Methods This study analyzed prospectively collected data from 30 consecutive SSc patients, excluding those with systemic hypertension and diabetes mellitus and a control group including 30 healthy female volunteers with a mean age of 35.6±7.7. Most SSC patients were females (28/30), with a mean age of 39±10.8. After obtaining informed consent, all participants underwent clinical evaluation and transthoracic echocardiography, including strain analysis. Results Left atrial reservoir (38.1±3.8 % vs. 45.33.7 %; p&amp;lt;0.001), conduit (21.82.7 % vs. 25.73.2 %; p&amp;lt;0.001), and contractile (16.23 % vs. 19.6±2 %; p&amp;lt;0.001) strain parameters were significantly reduced in the SSc population than the healthy controls. The LA stiffness index was also significantly higher in SSc patients (0.186±0.042 vs 0.138±0.018; p&amp;lt;0.001). The total emptying fraction (59.9±7 % vs. 64.73 %; p=0.003), expansion index (160.945.8 % vs. 185.224.1%; p=0.007), and passive emptying fraction (37.37.4 % vs. 40.7±8.5%; p=0.012) were significantly lower in SSc patients compared to the controls. However, the active emptying fraction showed no significant difference between the 2 groups. LA maximal volume was similar between the 2 groups. Conclusion Patients with systemic sclerosis demonstrate reduced LA phasic function even without LA enlargement, as compared to healthy individuals, based on 2D speckle-tracking echocardiography (STE).

Impact of left atrial stiffness measurement as a pre-procedural predictor of an extensive left atrial low-voltage area

Abstract Background The presence of a left atrial (LA) low-voltage area (LVA) after pulmonary vein isolation for atrial fibrillation (AF) is a strong predictor of recurrence and LVAs are often an additional ablation target. However, predicting the presence of an LVA before the procedure remains challenging. Purpose To assess the LA stiffness index as a preprocedural predictor of an extensive LVA. Methods We prospectively evaluated 74 patients who underwent catheter ablation for AF and high-density bipolar LA voltage mapping during sinus rhythm or high right atrial pacing. "LVA" was defined as an area with bipolar electrograms (&amp;lt;0.5 mV), while "extensive LVA" was defined as the presence of an LVA that covered more than 15% of the LA surface. Echocardiographic measurements, including the LA volume index (LAVi), E/e' ratio, LA reservoir strain (LASr), and LA stiffness index, calculated as the ratio of E/eʹ to LASr, were performed prior to catheter ablation in all patients. Results Overall, 17 patients (23.0%) had an extensive LVA. Patients with extensive LVAs were older (73 ± 7 vs. 66 ± 8 years; P=0.003), predominantly female (59% vs. 23%; P=0.01), and more frequently showed persistent AF (59% vs. 30%; P=0.04) in comparison to patients without extensive LVAs. According to a receiver operating characteristic curve analysis, the LA stiffness index was more accurate than the LAVi or LASr for predicting extensive LVAs (Figure), allowing using a cutoff value ≥0.6 with 73% sensitivity and 91% specificity. A multivariate logistic regression analysis revealed that the LA stiffness index was an independent predictor of an extensive LVA (odds ratio [OR], 44.11; 95% CI 3.83–507.47, P=0.002). Conclusion The LA stiffness index was a robust predictor of the extent of LVAs in AF patients and thus could be useful for the preprocedural selection of candidates for catheter ablation and to determine the most effective ablation strategies.

Are metabolically healthy obese individuals really a benign cardiovascular group? An analysis of 162,590 participants with measures of arterial stiffness in UK BIOBANK

Abstract Background There is conflicting evidence as to whether so called metabolically healthy but overweight and obese individuals are at increased cardiovascular risk or mortality. Purpose We assessed whether metabolic health correlates with vascular health among these individuals using severity of arterial stiffness as a proxy for vascular health and cardiovascular risk. Methods Participants in UK Biobank with body-mass index (BMI) and arterial stiffness index (ASI) recorded at initial assessment between 2006-2010, and free from stroke and myocardial infarction and not underweight (BMI&amp;lt;18.5kg/m2) were included. Participants were stratified by BMI (normal, overweight, obese) and presence of metabolic abnormalities (hypertension, diabetes, dyslipidaemia). The primary outcome was the severity of ASI analysed using multivariate-adjusted linear regression. Results Of 162,590 participants, 55.0% were female, mean age was 57 years (SD 8), 42.5% were overweight and 24.4% obese. Within the normal BMI strata, 50.7% had ≥1 metabolic abnormality. Compared to individuals with normal BMI and no metabolic abnormalities (ref group), increased weight or metabolic abnormalities were similarly associated with higher ASI; adjusted β-coefficient [β] 0.35, 95%CI 0.30 to 0.40 for participants with normal BMI and ≥1 metabolic abnormality; β 0.32, 95%CI 0.26 to 0.37 for overweight participants without metabolic abnormalities. Obese individuals with no metabolic abnormalities had higher ASI (β 0.65; 95%CI 0.57 to 0.74) but was lower than overweight participants with metabolic abnormalities (β 0.80; 95%CI 0.75 to 0.84). Obese participants with metabolic abnormalities had the highest ASI (β 1.07; 95%CI 1.02 to 1.12) among all six metabolic combinations, p&amp;lt;0.001 for each vs ref group. Sensitivity analysis suggested higher ASI with increasing number of metabolic abnormalities within BMI categories. Conclusion Excess weight and metabolic abnormalities, are independently associated with adverse measures of vascular health to a similar degree, suggesting that the so called metabolically healthy obese are not a benign group. Primary prevention strategies should be considered in overweight, or obese individuals even if metabolic abnormalities are absent.

Association between left atrial dysfunction and adverse outcomes after tricuspid valve surgery for atrial functional tricuspid regurgitation

Abstract Objectives To identify factors associated with clinical outcomes in patients undergoing tricuspid valve (TV) surgery for atrial functional tricuspid regurgitation (AF- TR). Methods Among 1,670 patients who underwent TV surgery between January 2000 and December 2020, we included 83 AF-TR patients (69.1±9.2 years, 50 women) who had severe TR without any cause other than atrial fibrillation. A comprehensive analysis of right ventricular (RV) and left atrial (LA) function on preoperative and postoperative echocardiography was performed. LA function was evaluated by LA emptying fraction (LAEF), LA reservoir strain, and LA stiffness index. The primary outcome was a composite of all-cause death and heart failure hospitalization during follow up after surgery. Results For a median of 39.9 (interquartile range 19.9 to 55.8) months, the primary outcome occurred in 20 (24.1%) patients. Patients with a primary outcome showed significantly lower LAEF (9.7±7.3 vs. 21.8±6.7 %, p&amp;lt;0.001) and LA reservoir strain, and higher LA stiffness index than those without. However, there was no difference in RV chamber size and functional parameters according to the occurrence of a primary outcome. The restricted cubic spline plot exhibited a significant relationship between LAEF and primary outcome. The low baseline LAEF (&amp;lt;17%) group showed a poorer outcome than the high LAEF group (log rank p&amp;lt;0.001). In the Cox regression analysis, the low LAEF (&amp;lt;17%) was independent predictor for primary outcome (adjusted hazard ratio 13.5, 95% confidence interval 3.1–58.6). Conclusion In patients undergoing TV surgery with AF-TR, preoperative LA dysfunction was independently associated with adverse outcomes.Figure1

Interaction between right atrial function reserve and liver stiffness after complete repair of tetralogy of fallot: a pilot study

Abstract Background Impaired right atrial mechanics is reported in patients with repaired tetralogy of Fallot (TOF) and is associated with liver stiffness. However, whether right atrial functional reserve correlates with liver stiffness is unknown. Purpose This study tested the hypothesis that right atrial reserve capacity is limited in patients with repaired TOF and explore its relationships with right ventricular function and liver stiffness. Methods 10 patients (45% male) aged 19.04 ± 3.76 at 16.70 ± 4.30 years after repair and 15 controls (60% male, aged 20.31 ± 1.25 years) were studied. RA mechanics was assessed by speckle-tracking echocardiography (STE) at rest and during bicycle exercise, with quantification of positive, negative, and total strain, and strain rates at ventricular systole (aSRs), early diastole (aSRed), and atrial contraction (aSRac). Right atrial function reserve (RAFR) is calculated as (∆RA total strain x [1-1/ RA total strain at baseline]). RV systolic and diastolic function was quantified using Doppler interrogation and STE. Hepatic shear wave velocity (c) and tissue elasticity (E) were measured using two-dimensional shear wave elastography. Results At rest, patients had significantly lower RA positive, negative and total strain, aSRs and aSRed than control subjects (all P&amp;lt;0.02). Shear wave velocity and hepatic E value were significantly higher in patients than controls (both P&amp;lt;0.02). Compared with controls, patients had significantly lower RA positive, negative and total strain, aSRs, aSRed, and aSRac at exercise (all P&amp;lt;0.05). No significant difference in hepatic shear wave velocity and tissue elasticity were found between patients and control subjects at exercise (all P&amp;gt;0.05). Both baseline liver stiffness indices correlated negatively with RAFR, RA positive and total strain and aSRed at exercise (p&amp;lt;0.05 for all). RV function parameters, including baseline trans-tricuspid early and late diastolic inflow velocity (E, A), systolic, early and late diastolic tricuspid annular velocity (s, e, a), isovolumetric acceleration (IVA), RV systolic and diastolic reserve correlated significantly with RA positive and total strain at exercise (P&amp;lt;0.05 for all). Conclusions In young adults with repaired TOF, right atrial function reserve is impaired, and is associated with increased liver stiffness and RV dysfunction.RA mechanics from rest to exerciseStress RA mechanics and liver stiffness

Optimal blood pressure values to reduce arterial stiffness, an analysis from UK Biobank

Abstract Introduction Increased arterial stiffness is a powerful independent risk factor for adverse cardiovascular events. While pulse wave velocity has been used extensively as a biomarker of vascular health reflecting functional and structural arterial changes, its use in clinical practice was limited. The Arterial Stiffness Index (ASI) simplifies the assessment of arterial stiffness using a pulse waveform obtained at the finger with an infrared sensor with BP measured using an automated device. Age and raised blood pressure (BP) are major contributors to increased arterial stiffness, but time trajectories of ASI in the general population and optimal BP values to reduce arterial stiffening are scarcely known. Purpose To establish temporal changes of ASI and identify BP values associated with longer-term improvement of arterial stiffness. Methods The study analysed data from UK Biobank (baseline n=154,684, median age 54, interquartile range (IQR) [40-72] years; 52% female; 91% white, 28% hypertension). ASI was measured using PulseTrace PCA2 device (CareFusion, USA) at baseline with measurements repeated in 4617 individuals after a median follow up of 3.0, IQR [2.8-3.3] years. BP was measured during the same time points. Multivariable (adjusted for age, sex, diabetes, and use of BP-lowering drugs) linear regression was used to determine the association of BP with baseline and the association of BP and ASI changes during follow up. ROC analysis was used to determine BP values associated with improvement (reduction) of ASI during follow up. Continuous data are presented as median [IQR] and compared using Wilcoxon test. R software packages were used for analyses. Results At baseline, ASI (m/sec) was higher in those with systolic BP (SBP) &amp;gt;140 mmHg (9.60 [7.15-11.85] vs. 8.67 [6.77-10.70] for SBP ≤140 mmHg, p&amp;lt;0.001) and in those with diastolic BP (DBP) &amp;gt;90 mmHg (9.90 [7.48-12.16] vs 8.81 [6.78-10.90] for DBP ≤90 mmHg, p&amp;lt;0.001). Both SBP and DBP were independently associated with ASI at baseline (B±SE 0.08±0.02 and 0.79±0,29m, respectively; p&amp;lt;0.001 for both). During follow up, the population level SBP remained unchanged (change 0 [-8 - 8] mmHg), with some reduction in DBP (-1.0 [-6.0 - 3.5]) mmHg. SBP reduced in 2234 (48%) and DBP in 2517 (55%). ASI increased by 0.56 [-1.46 - 2.78] m/s, with ASI reduction observed in 1935 (42%). An increase in DBP but not in SBP was independently associated with an increase in ASI (B±SE DBP 0.04±0.01, p&amp;lt;0.001; SBP 0.007±0.006, p=0.22; DBP 0.04±0.007, p&amp;lt;0.001). The baseline BP was predictive of the magnitude of changes in ASI: SBP 132 mmHg (AUC 0.53, p=0.001) and DBP 83 mmHg (AUC 0.54, p&amp;lt;0.001). Conclusions Increased arterial stiffness is associated with higher BP, particularly with higher DBP. Raised ASI is reversible, providing BP is adequately controlled with optimal BP being &amp;lt;132/83 mmHg.

Differential postnatal cardiovascular course of donor-recipient twins and associated pathophysiology-a cohort study.

Fetal echocardiography in twin to twin transfusion pregnancies treated with photocoagulation noted impaired cardiac function. Systematic information about cardiac structure or function and arterial distensibility after birth is not available. This study evaluated cardiovascular function and arterial dynamic properties in survivors of twin to twin transfusion syndrome. Eleven pairs of donor-recipient twins were compared with each other, and with 20 singletons of comparable gestational age. The twin cohort was born at 31.5±2 weeks gestational age; birthweights of donors-recipients were comparable (donors: 1358±421g vs recipients: 1617±460g, P=0.2). Significant inter-twin differences were noted for cardiac function parameters. Recipients had greater septal thickness (donors: 2.3±0.15 vs recipients: 2.7±0.36mm, P=0.01) and globularity (lower sphericity index [donors: 1.76±0.1 vs recipients: 1.62±0.12, P=0.009]). They also had lower cardiac function (tricuspid annular plane systolic excursion [donors: 4.6±0.5 vs recipients: 4.1±0.4mm, P=0.02) and right ventricular fractional area change [donors: 30±1 vs recipients: 27.7±1.3%, P=0.0001]). Comparing with singletons, differences were statistically more significant for recipients. Arterial distensibility however, was more affected in donors (higher arterial wall stiffness index [donors: 2.5±0.2 vs recipients: 2.2±0.2, P=0.008] and lower pulsatile diameter [donors: 51±5 vs recipients: 63±10 µm, P<0.0001). Comparing with singletons, the differences were statistically more significant for donors. Evaluation in the neonatal period noted that cardiac function and arterial distensibility is affected in TTTS twins. These cohorts will benefit from close postnatal follow up for resolution of cardiac and arterial impairments.

Assessment of metabolic indicators of the cardiovascular system in children with nephrotic syndrome

Objective: to evaluate the metabolic parameters of the cardiovascular system in nephrotic syndrome in children Material and methods: 110 children hospitalized with nephrotic syndrome in the nephrology department of the Samarkand Regional Children’s Multidisciplinary Medical Center were examined. Results: Renocardial syndrome with nephrotic syndrome develops in 64.8% of cases, the majority of patients are children 3-6 years of age (44.1%), with a predominance of boys (58.8%). In a cardiometric study in patients with nephrotic syndrome, renocardial syndrome is manifested by significant changes in metabolic and adaptation parameters: oxygen and lactate content - by 1.5 times, creatine phosphate - by 20%, tension index - by 4.8 times and vascular stiffness index - by 5.2 times. Conclusion: Deviation of cardiometry indicators in different age groups indicates a decrease in the intensity of blood circulation in organs and systems, indicating a significant load on the cardiovascular system in nephrotic syndrome.

Local carotid stiffness, hemodynamic forces and blood viscosity in patients with cerebral lacunar infarctions.

The carotid stiffness is an important factor in the pathogenesis of cerebrovascular small vessel disease. Our study aimed to evaluate the relation of the local arterial stiffness of the common carotid artery (CCA) to the hemodynamic forces and blood viscosity in patients with cerebral lacunar infarctions (LI). Twenty-two patients with chronic LI and 15 age-matched controls were examined. An ultrasound examination of the CCA intima-media thickness (IMT), the parameters of local CCA stiffness: distensibility (DC) and compliance coefficients (CC), α and β stiffness indices and pulse wave velocity (PWV) was performed. The local hemodynamic forces were calculated: circumferential wall tension (CWT) and wall shear stress (WSS). Whole blood viscosity (WBV) and shear stresses at shear rates of 0.277 s-1 to 94.5 s-1 were measured in patients and controls. Higher values of IMT, a significant decrease of DC and CC and an increase of α and β stiffness indices and PWV in the LI patients compared to the controls were obtained. A parallel significant increase in CWT and a decrease in WSS was found. An increase in WBV and a significant increase in shear stresses were detected. In the LI patients, the increased stiffness indices were associated with an increase in age, cholesterol and WBV at higher shear rates in the left CCA. In the controls, the IMT and stiffness indices correlated significantly with the hemodynamic factors and WBV in both CCAs, while the stiffness indices correlated with the hemodynamic forces in the left CCA. The results of the present study demonstrate different associations of the local carotid stiffness indices with the hemodynamic forces and WBV in patients with LI and controls.

Efficacy and safety of inhaled molecular hydrogen therapy in patients with respiratory failure due to chronic obstructive pulmonary disease exacerbation in post-COVID period

Molecular hydrogen (H2) is a powerful antioxidant and anti-apoptotic agent. H2 has been studied in a number of clinical studies in the recent years.The aim of this research was to investigate the efficacy and safety of H2 inhalation therapy in patients with hypoxemic and hypercapnic respiratory failure (RF) against exacerbation of chronic obstructive pulmonary disease (COPD) in the post-COVID (Corona Virus Disease 2019) period.Methods. The randomized prospective parallel comparative study included patients (n = 60: 40 men aged 71.2 ± 1.8 years, 20 women aged 70.9 ± 2.8 years) with a post-COVID-19 exacerbation of COPD complicated by hypoxemic/hypercapnic RF. The patients were divided into 2 groups: group 1 (main) (n = 30: 18 men, 12 women), group 2 (control) (n = 30: 18 men, 12 women). To maintain arterial blood saturation ≥ 90 %, patients in both groups received respiratory support (non-invasive ventilation) using the Prisma 25ST device (Lowenstein Medical, Germany) in the BiPAP S/T mode (BiLevel Positive Airway Pressure Spontaneous/Time spontaneous/forced mode 20–24/4–6 cm H2O and O2, respectively; the fractional oxygen concentration in the inhaled gas mixture was ≥ 24%). In addition to standard treatment, patients in the main group received additional H2 therapy (Suisonia device, Japan) through a nasal cannula for 90 minutes daily for 14 days.Results. In patients of the main group, a decrease in the stiffness index was detected from 14.6 ± 1.2 to 6.2 ± 0.6 m/s, and the arterial blood lactate level – from 2.84 ± 0.1 to 0.02 ± 0.1 mmol/l (p &lt; 0.001), the calculated shunt fraction Qs/Qt (venous admixture) – from 27.21 ± 3.4 to 7.14 ± 1.23 (p &lt; 0.01) and an increase in the following parameters: reflection index – from 42.2 ± 2.0 to 66.2 ± 4.9% (p &lt; 0.05), virus-specific IgG level – from 134 ± 125 to 669 ± 164 (p &lt; 0. 05), blood flow velocity in arterioles – from 473 ± 108 to 868 ± 64 μm/s (p &lt; 0.05), blood flow velocity in venules – from 299 ± 56 to 862 ± 69 μm/s (p &lt; 0.05), the 6-minute walk distance – from 57.1 ± 4.4 to 328.9 ± 33.7 m (p &lt; 0.05).Conclusion. H2 inhalations were safe and increased the therapeutic effect when added to standard therapy for patients with hypoxemic and hypercapnic RF during exacerbation of COPD in the post-COVID period.

Testing and evaluation of PVCC nano layered reinforced concrete T-beam: Experimental study

This study examines the performance of reinforced concrete T-beams strengthened with PVCC nano layering and basalt fiber fabric wrapping. TP3, a PVCC nano-layered specimen with 1.2% PVA fiber, and TB2, a basalt fiber fabric-wrapped beam, outperform the other specimens. TP3 has a first fracture load of 112 kN and a maximum ultimate load of 165 kN, with 1.66 times the ductility and 1.51 times the stiffness of the control beam (T0). TP3 also has 1.61 times more energy absorption and the highest energy index, 1.46 times that of T0. TB2 can withstand a maximum ultimate load of 185 kN and has higher ductility, stiffness, energy absorption, and energy index than T0. The experimental results are validated by finite element analysis, which provides useful insights into strengthening procedures in structural engineering applications.

24-hour arterial stiffness profile in asthma patients with obesity

Obesity is an important comorbidity in patients with asthma, and this combination is associated with increased cardiovascular risk.The aim of the study was to evaluate 24-hour arterial stiffness in asthma patients with excess body weight and obesity.Methods. The study included 100 patients with asthma who were divided into three groups according to their body mass index (BMI). The first group included 36 patients with normal BMI, the second – 40 patients with excess body weight, the third – 24 patients with obesity. The vascular stiffness parameters were evaluated in all patients using BPlab. Аоrtic pulse wave velocity, augmentation index, and arterial stiffness index were also assessed.Results. The 24-hour arterial stiffness, daytime and nighttime arterial stiffness values were increased in the patients with asthma and obesity. More than 80% of the asthma patients with obesity have higher pulse wave velocity in the daytime.Conclusion. Patients with bronchial asthma with obesity represent the risk of developing cardiovascular diseases and their complications.

Left Atrial Structural and Functional Changes in Adults with Congenital Septal Defects and Paroxysmal Atrial Fibrillation.

Aims. To identify the difference between adult patients with septal defects and paroxysmal atrial fibrillation (AF) and patients without a history of arrhythmia using the left atrial (LA) volume and function parameters, to reveal the parameters associated with AF development. Methods and results. In this prospective study, 81 patients with septal defects and left-to-right shunts were enrolled between 2021 and 2023 and divided into two groups: with paroxysmal AF and without AF. Left atrial function was analyzed based on the indexed left atrial volumes (LAVI and preA-LAVI), ejection fraction (LAEF), expansion index (LAEI), reservoir (LAS-r), conduit (LAS-cd) and contractile (LAS-ct) strain, and stiffness index (LASI) using a Philips CVx3D ultrasound system (Philips, Amsterdam, The Netherlands) and corresponding software. In total, 26 patients with paroxysmal atrial fibrillation (mean age: 59.6 ± 11.7 years, female: 80.8%) and 55 patients with septal defects without any history of arrhythmias (mean age: 44.8 ± 11.6 years, female: 81.8%) were included. All patients were in the NYHA class I or II at baseline. Our findings demonstrated a significant difference between all LA function parameters in the two groups. Upon univariable analysis, the LAVI, preA-LAVI, LASI, LAEF, LAEI, LAS-r, LAS-c, LAS-ct, age, cardiac index, E/A, and RV pressure were found to be associated with AF. The multivariate analysis identified LAVI (OR 1.236, 95% CI 1.022-1.494, p = 0.03), LAS-r (OR 0.723, 95% CI 0.556-0.940, p = 0.02), and LAS-ct (OR 1.518, 95% CI 1.225-1.880, p < 0.001) as independent predictors of AF development. The proposed model demonstrated high sensitivity and specificity with an adjusted classification threshold of 0.38 (AUC: 0.97, 95% CI 0.93-1.00, sensitivity 92% and specificity 92%, p < 0.001). Conclusions. The assessment of LA function using speckle-tracking echocardiography demonstrated significantly different values in the AF group among patients with congenital septal defects. This technique can therefore be implemented in routine clinical management. The key message. Atrial fibrillation development in adult patients with congenital septal defects and a left-to-right shunt is associated with the changes in left atrial function under conditions of an increased preload.

Association Between Arterial Stiffness Index and Age-Related Diseases: A Mendelian Randomization Study.

Arterial stiffness is an emerging indicator of cardiovascular risk, but its causal relationship with a variety of age-related diseases is unclear. The objective is to assess the causal relationship between arterial stiffness index (ASI) and age-related diseases by Mendelian randomization (MR) analysis. We obtained instrumental variables associated with age-related diseases from genome-wide association studies (GWAS) of 484,598 European individuals, and data for ASI were obtained from the UK Biobank GWAS of 127,127 participants. We used the inverse variance-weighted as the primary analysis method. In addition, several sensitivity analyses including MR-Egger, weighted-median (WM), Mendelian randomization pleiotropy residual sum and outlier, and Cochran's Q test were performed to test the robustness of the results. Reverse MR analysis was also performed to assess reverse causal relationships between age-related diseases and ASI. We verified the causal relationship between eight age-related diseases and ASI, of which cardiovascular disease (β = 0.19), gallbladder disease (β = 0.85), liver, biliary, or pancreas problem (β = 1.02), hypertension (β = 0.19), joint disorder (β = 0.53), and esophageal disorder (β = 2.10) elevated ASI. In contrast, hyperthyroidism or thyrotoxicosis (β = -2.17) and bowel problems (β = -1.83) may reduce ASI. This MR analysis reveals causal relationships between ASI and several age-related diseases. ASI is expected to be a potential indicator of health conditions for older populations.