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This article discusses a study on the estimation of regurgitation in patients with percutaneous left ventricular assist devices (PLVAD) during full support. The study proposes an estimation system based on a regurgitation model and uses an unscented Kalman filter (UKF) as an estimation approach. The research findings demonstrate that the proposed system can accurately estimate regurgitation during PLVAD full support, providing valuable information for clinical practitioners. The text also discusses the use of the UKF algorithm to estimate regurgitation caused by positional abnormalities after the implantation of a partial left ventricular assist device (PLVAD). The study analyzes experimental data for different degrees of positional offset and finds that the estimation error is minor for moderate and severe offsets, but slightly larger for mild offset. The UKF algorithm is shown to accurately estimate regurgitation in cases of cardiogenic shock. However, further research is needed to improve the accuracy of estimation and validate the results in larger animal models and clinical patient populations. The text also discusses the use of the UKF algorithm to estimate regurgitation status in patients with cardiogenic shock. The algorithm shows relatively accurate estimation, but further consideration is needed to improve accuracy by accounting for the impact of myocardial contractility on pump performance. Real-time observation of flow waveforms can assist in detecting regurgitation events and improving patient safety. The study is limited to a computational approach and a mock circuit, but future developments should incorporate animal and human data for [Extracted from the article]

To detect the expression of inflammatory factors such as interleukin-1β (IL-1β), interleukin-6 (IL-6), transforming growth factor (TGF-β), and tumor necrosis factor (TNF-α) in the tumor tissue of ventricular septal defect (VSD) in congenital heart disease and to explore the role of inflammatory response in the formation of aneurysmal perimembranous VSD(APVSD). Children with APVSD of congenital heart disease treated by surgery were selected and divided into true aneurysmal perimembranous group (TAP group) and pseudoaneurysmal perimembranous group (PAP group) according to echocardiography and surgical findings. There were 15 children in the TAP group and 31 in the PAP group. The aneurysmal perimembranous tissue of the two groups of children was collected during the operation. IL-1β, IL-6, TGF-β, and TNF-α were positively expressed in the aneurysmal perimembranous tissue of the two groups, and the expression levels of all inflammatory factors in the PAP group were higher than those in the TAP group, and the difference was statistically significant (P < 0.05). The expression levels of IL-1β, IL-6, TGF-β, and TNF-α in the aneurysmal perimembranous tissue of the two groups were negatively correlated with the width of the APVSD breach. IL-1β, IL-6, TGF-β, and TNF-α may be involved in the occurrence and development of APVSD through inflammatory mechanism. [ABSTRACT FROM AUTHOR]

Heart auscultation is a convenient tool for early diagnosis of heart diseases and is being developed to be an intelligent tool used in online medicine. Currently, there are few studies on intelligent diagnosis of pediatric murmurs due to congenital heart disease (CHD). The purpose of the study was to develop a method of intelligent diagnosis of pediatric CHD murmurs. Phonocardiogram (PCG) signals of 86 children were recorded with 24 children having normal heart sounds and 62 children having CHD murmurs. A segmentation method based on the discrete wavelet transform combined with Hadamard product was implemented to locate the first and the second heart sounds from the PCG signal. Ten features specific to CHD murmurs were extracted as the input of classifier after segmentation. Eighty-six artificial neural network classifiers were composed into a classification system to identify CHD murmurs. The accuracy, sensitivity, and specificity of diagnosis for heart murmurs were 93%, 93.5%, and 91.7%, respectively. In conclusion, a method of intelligent diagnosis of pediatric CHD murmurs is developed successfully and can be used for online screening of CHD in children. [ABSTRACT FROM AUTHOR]

Background: Some patients with sepsis are found with accompanying mild hypothermia (ACMH); however, the effects of ACMH on the patients with sepsis are poorly understood.Objective: To compare the impacts of ACMH and artificial mild hypothermia (ATMH) on mortality, systemic inflammatory reactions, and organ functions in mice with sepsis.Methods: Septic mouse models were induced and divided into ACMH, un-hypothermia, keep normothermia, and ATMH groups, according to the anal temperature and the thermic intervention strategy. The mortality rate, serum levels of tumor necrosis factor α (TNF-α), interferon γ (IFN-γ), and interleukin (IL)-4 and liver and renal functions of the mice in each group were recorded. Liver, lung, and renal tissues of the mice were stained and examined under optic microscope.Results: The mortality rate in the ACMH group was the lowest among all the sepsis groups. Increased serum levels of TNF-α, IFN-γ, and IL-4 and impairments of the liver and renal functions were found in the septic mice. The serum levels of TNF-α, IFN-γ, and IL-4 were significantly lower and the liver and renal functions of ACMH group were not impaired significantly as compared with other sepsis groups. Pathological examinations of the lung, liver, and renal tissues showed that the ACMH group were with the lowest pathological score among all the sepsis groups.Conclusion: Accompanying mild hypothermia and ATMH could both reduce mortalities in mice with sepsis, and ACMH could reduce mortality even lower, and more alleviate systemic inflammatory responses and the damages in lung, kidney, and other organs were lighter. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the influence of mild hypothermia on the number of CD11b+ Gr-1+ myeloid-derived suppressor cells (MDSCs) induced by lipopolysaccharide (LPS) injection in mice with sepsis.Methods: BALB/c mice were administered LPS to establish a mouse model of sepsis. Then, these mice were randomly divided into 3 groups: the mild hypothermia plus LPS group, the normothermia plus LPS group, and the LPS group. The normal control group was injected the same amount of 0.9% sodium chloride solution. The ratio of CD11b+ Gr-1+ MDSCs in the mouse spleen and bone marrow was determined at 6, 12, 24, 48, and 72 hours after LPS injection and after injected 0.9% sodium chloride solution.Results: Compared with the control group, the number of MDSCs in the spleen in the sepsis group increased gradually, and the difference was significant at 12 hours after injection (P<.01). Moreover, the number of MDSCs was the lowest in the mild hypothermia group, and there was a significant difference than the other 2 groups at 48 hours (P<.01). The number of MDSCs in the bone marrow increased gradually, and the difference between the sepsis and control groups was significant at 24 hours (P<.01). The number of MDSCs in the mild hypothermia group was the lowest, and there was a statistically significant difference than the other 2 groups (P<.05).Conclusion: Mild hypothermia inhibited the production and accumulation of MDSCs induced by LPS administration in septic mice. [ABSTRACT FROM AUTHOR]

Sepsis-associated encephalopathy (SAE) is a common complication of sepsis that may seriously affect the prognosis and quality of life of patients with sepsis. Microglial activation is vital to the neuroinflammation and the pathology of SAE. In the present study, in vitro cultured BV-2 microglial cells stimulated with lipopolysaccharide (LPS) were employed as a model of microglia activation. The altered profiles of long noncoding (lnc)RNAs, circular (circ)RNAs and mRNAs in BV-2 cells after 4 h of LPS exposure were arrayed by using the Agilent competing endogenous (ce)RNA Microarray Chip. Using fold change >2 and P<0.05 as the cutoff criteria, 1,135 mRNAs and 2,488 lncRNAs were determined to be upregulated and 630 mRNAs and 744 lncRNAs to be downregulated. The number of differentially expressed circRNAs was lower, with 140 upregulated and 123 downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis of DE mRNAs suggested that inflammatory responses, as well as lipid metabolism, were involved in microglial activation. Furthermore, analyses of ceRNA networks of the lncRNA-miRNA-mRNA or circRNA-miRNA-mRNA interrelations were performed. The present study revealed a multitude of novel candidate mRNAs, lncRNAs and circRNAs involved in microglial activation, which may improve the current knowledge on neuroinflammation and provide potential therapeutic targets for SAE. [ABSTRACT FROM AUTHOR]

Objective. A percutaneous left ventricular assist device (PLVAD) can be used as a bridge to heart transplantation or as a temporary support for end-stage heart failure. Transvalvularly placed PLVADs may result in aortic regurgitation due to unstable pump position during fully supported operation, which may diminish the pumping effect of forward flow and predispose to complications. Therefore, accurate characterization of aortic regurgitation is essential for proper modeling of heart-pump interactions and validation of control strategies. Approach. In the present study, an improved aortic valve model was used to analyze the severity of regurgitation produced by different pump position offsets. The link between pump position offset degree and regurgitation is validated in the fixed speed mode, and the influence of pump speed on regurgitation is verified in the variable speed mode, using the mock circulatory loop (MCL) experimental platform. Main results. The greater the pump offset and the more severe the regurgitation, the more carefully the pump speed needs to be managed. To avoid over-pumping, the recommended pump speed in this study should not exceed 30 000 rpm. Significance. The modeling approach provide in this study not only makes it easier to comprehend the impact of regurgitation events on the entire interactive system during mechanical assistance, but it also aids in providing timely alerts and suitable management measures., (© 2023 Institute of Physics and Engineering in Medicine.)

Objective . Impedance cardiography (ICG) is a noninvasive and continuous method for evaluating stroke volume and cardiac output. However, the ICG measurement is easily interfered due to respiration and body movements. Taking into consideration about the spectral correlations between the simultaneously collected ICG, electrocardiogram (ECG), and acceleration signals, this paper introduces a two-step spectrum denoising method to remove motion artifacts of ICG measurements in both resting and exercising scenarios. Approach . First, the major motion artifacts of ECG and ICG are separately suppressed by the spectral subtraction with respect to acceleration signals. The obtained ECG and ICG are further decomposed into two sets of intrinsic mode functions (IMFs) through the ensemble empirical mode decomposition. We then extract the shared spectral information between the two sets of IMFs using the canonical correlation analysis in a spectral domain. Finally, the ICG signal is reconstructed using those canonical variates with largest spectral correlations with ECG IMFs. Main results . The denoising method was evaluated for 30 subjects under both resting and cycling scenarios. Experimental results show that the beat contribution factor of ICG signals increases from its original 80.1%-97.4% after removing the motion artifacts. Significance . The proposed denoising scheme effectively improves the reliability of diagnosis and analysis on cardiovascular diseases relying on ICG signals., (© 2021 Institute of Physics and Engineering in Medicine.)

Background: Intrahepatic cholestasis of pregnancy (ICP) is a common disease affecting up to 5% of pregnancies and which can cause fetal arrhythmia and sudden intrauterine death. We previously demonstrated that bile acid taurocholate (TC), which is raised in the bloodstream of ICP, can acutely alter the rate and rhythm of contraction and induce abnormal calcium destabilization in cultured neonatal rat cardiomyocytes (NRCM). Apart from their hepatic functions bile acids are ubiquitous signalling molecules with diverse systemic effects mediated by either the nuclear receptor FXR or by a recently discovered G-protein coupled receptor TGR5. We aim to investigate the mechanism of bile-acid induced arrhythmogenic effects in an in-vitro model of the fetal heart., Methods and Results: Levels of bile acid transporters and nuclear receptor FXR were studied by quantitative real time PCR, western blot and immunostaining, which showed low levels of expression. We did not observe functional involvement of the canonical receptors FXR and TGR5. Instead, we found that TC binds to the muscarinic M(2) receptor in NRCM and serves as a partial agonist of this receptor in terms of inhibitory effect on intracellular cAMP and negative chronotropic response. Pharmacological inhibition and siRNA-knockdown of the M(2) receptor completely abolished the negative effect of TC on contraction, calcium transient amplitude and synchronisation in NRCM clusters., Conclusion: We conclude that in NRCM the TC-induced arrhythmia is mediated by the partial agonism at the M(2) receptor. This mechanism might serve as a promising new therapeutic target for fetal arrhythmia.