To visualize and quantify the hemodynamics in the aortic arch in normal individuals, we used velocity distribution, retrograde flow, vortex formation, and mean energy loss (mEL) at different cardiac cycles in our study. We performed Vector flow mapping (VFM) analysis by using echocardiography in 87 healthy volunteers. The results showed that ① in different sections of the aortic arch, a skewed peak flow velocity (Vp) always appeared in the period of rapid ejection but in different distribution. The systolic flow in the entire aortic arch rose rapidly from near-zero at the point of iso-volumetric contraction to the peak velocity at the period of rapid ejection, and then decreased gradually; ② In the period of iso-volumetric relaxation, retrograde flow and vortex were observed in all subjects in the inner wall of the entire aortic arch; and ③ The change rule of mEL in the entire aortic arch was similar to that of flow velocity. VFM can provide insights into the intra-aortic arch flow patterns, and offer essential fundamentals about flow features associated with common aortic diseases.
Hemodynamics plays a vital role in the development and progression of cardiovascular diseases, and is closely associated with changes in morphology and function. Reliable detection of hemodynamic changes is essential to improve treatment strategies and enhance patient prognosis. The combination of computational fluid dynamics with cardiovascular imaging technology has extended the accessibility of hemodynamics. This review provides a comprehensive summary of recent developments in the application of computational fluid dynamics for cardiovascular hemodynamic assessment and a succinct discussion for potential future development.
Objective To identify potential hub genes and key pathways in the early period of septic shock via bioinformatics analysis. MethodsThe gene expression profile GSE110487 dataset was downloaded from the Gene Expression Omnibus database. Differentially expressed genes were identified by using DESeq2 package of R project. Then Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were constructed to investigated pathways and biological processes using clusterProfiler package. Subsequently, protein-protein interaction (PPI) network was mapped using ggnetwork package and the molecular complex detection (MCODE) analysis was implemented to further investigate the interactions of differentially expressed genes using Cytoscape software. Results A total of 468 differentially expressed genes were identified in septic shock patients with different responses who accepted early supportive hemodynamic therapy, including 255 upregulated genes and 213 downregulated genes. The results of GO and the KEGG pathway enrichment analysis indicated that these up-regulated genes were highly associated with the immune-related biological processes, and the down-regulated genes are involved in biological processes related to organonitrogen compound, multicellular organismal process, ion transport. Finally, a total of 23 hub genes were identified based on PPI and the subcluster analysis through MCODE software plugin in Cytoscape, which included 19 upregulated hub genes, such as CD28, CD3D, CD8B, CD8A, CD160, CXCR6, CCR3, CCR8, CCR9, TLR3, EOMES, GZMB, PTGDR2, CXCL8, GZMA, FASLG, GPR18, PRF1, IDO1, and additional 4 downregulated hub genes, such as CNR1, GPER1, TMIGD3, GRM2. KEGG pathway enrichment analysis and GO functional annotation showed that differentially expressed genes were primarily associated with the items related to cytokine-cytokine receptor interaction, natural killer cell mediated cytotoxicity, hematopoietic cell lineage, T cell receptor signaling pathway, phospholipase D signaling pathway, cell adhesion molecules, viral protein interaction with cytokine and cytokine receptor, primary immunodeficiency, graft-versus-host disease, type 1 diabetes mellitus. Conclusions Some lymphocytes such as T cells and natural killer cells, cytokines and chemokines participate in the immune process, which plays an important role in the early treatment of septic shock, and CD160, CNR1, GPER1, and GRM2 may be considered as new biomarkers.
The development and progression of atherosclerosis and thrombosis are closely related to changes of hemodynamics parameters. Ultrasonic pulse wave Doppler technique is normally used for noninvasively blood flow imaging. However, this technique only provides one-dimensional velocity and depends on the angle between the ultrasound beam and the local velocity vector. In this study, ultrasonic particle image velocimetry method was used to assess whole field hemodynamic changes in normal blood vessels. By using the polynomial fitting method, we investigated the velocity gradient and assessed the shear in different blood flow velocity of 10 healthy rats. It was found that using four polynomial fitting could result in optimal measurement results. The results obtained by ultrasonic particle image velocimetry accorded with the results obtained using Doppler technique. The statistical average of cyclical vessel wall shear stress was positively related to the locational mean velocity. It is proven that ultrasonic particle image velocimetry method could be used to assess directly the real-time whole field hemodynamic changes in blood vessels and was non-invasively, and should be a good prosperous technique for monitoring complex blood flow in stenotic arteries.
Hematopoietic stem cells (HSCs) are tissue specific stem cells that replenish all mature blood lineages during the lifetime of an individual. Hematopoietic cell clusters in the aorta of vertebrate embryos play a pivotal role in the formation of the adult blood system. Recently, people have learned a lot about the embryonic HSCs on their development and homing. During their differentiation, HSCs are regulated by the transcription factors, such as Runx1 and Notch signaling pathway, etc. MicroRNAs also regulate the self-renewal and differentiation of hematopoietic stem/progenitor cells on the post-transcriptional levels. Since the onset of circulation, the formation of HSCs and their differentiation into blood cells, especially red blood cells, are regulated by the hemodynamic forces. It would be of great significance if we could treat hematologic diseases with induced HSCs in vitro on the basis of fully understanding of hemotopoietic stem cell development. This review is focused on the advances in the research of HSCs' development and regulation.
Objective To investigate the correlation of intracranial arachnoid cyst (IAC) with epilepsy and the possible mechanism of seizure induced by IAC. Methods Patients with IAC, who were treated in West China Hospital of Sichuan University between January 2009 and January 2019, were included and divided into IAC with epilepsy group and IAC without epilepsy group according to whether they were diagnosed with epilepsy. We collected the IAC location information of all subjects after the establishment of a three-dimensional spatial coordinate system of MRI images. Computational fluid dynamics technology was used to establish a blood vessel model in cyst area and perform hemodynamic analysis basing on contrast-enhanced CT images. Results A total of 72 patients were enrolled, including 24 in the IAC with epilepsy group and 48 in the IAC without epilepsy group. There was no significant difference between the two groups in terms of sex, age, IAC location, the volumes or the maximum diameters of IAC (P>0.05). Consecutive areas formed by the seven high-risk areas found in the IAC with epilepsy group were located in the temporal area. The seven high-risk areas were simultaneous IAC location in 5 patients in the IAC with epilepsy group and in 1 patient in the IAC without epilepsy group, and the difference was statistically significant (χ2=5.114, P=0.024). Comparison of the hemodynamic parameters between the two types of vascular models revealed similar pressure changes and blood pressure parameters, with lower blood flow and higher mean vascular wall shear stress in the IAC with epilepsy group. Conclusions IAC may cause epilepsy by increasing adjacent blood vessel stenosis and blood vessel wall shear stress through cyst space-occupying effect. The most common location of IAC with epilepsy is the temporal area. The occupying effect of IAC should be considered in the location of epileptogenic foci before surgery for IAC patients with epilepsy.
Quantitative measurement of strain distribution of arterial vessel walls due to pulsatile blood flow within the vascular lumen is valuable for evaluating the elasticity of arterial wall and predicting the evolution of plaques. The present paper shows that the three-dimensional (3D) strain distribution are estimated through uni-directional coupling for 3D vessel and blood models reconstructed from intravascular ultrasound (IVUS) images with the computational fluid dynamics (CFD) numerical simulation technique. The morphology of vessel wall and plaques as well as strain distribution can be visually displayed with pseudo-color coding.
Objective To investigate the clinical efficacy of mitral valve repair technique in the treatment of rheumatic mitral valve lesions. Methods The clinical data of patients diagnosed with rheumatic mitral valve lesions and undergoing mitral valve repair under extracorporeal circulation in our department from 2021 to 2022 were retrospectively analyzed. Results A total of 100 patients were collected, including 78 females and 22 males with an average age of 52 years. There were no secondary open heart or death in the whole group. Extracorporeal circulation time was 136.3±33.1 min, aortic cross-clamping time was 107.6±27.5 min, ventilator use time was 12.9±5.9 h, ICU stay was 2.6±1.4 d, and vasoactive medication use was 823.4±584.4 mg. Before and after the surgery, there were statistical differences in the left ventricular end diastolic diameter, left atrial end systolic diameter, effective mitral valve orifice area, shortening rate of left ventricular short axis, mitral E-peak blood flow velocity, mean mitral transvalvular pressure difference, mitral pressure half-time, and cardiac function graded by New York Heart Association (P＜0.05). While there was no statistical difference in left ventricular ejection fraction or left ventricular end-diastolic volume (P>0.05). Conclusion Overall repair of rheumatic mitral valve lesions can significantly improve the cardiac function and hemodynamics of the patients, and is a good choice for patients with rheumatic mitral valve lesions.
Surgical intervention for chronic thoracoabdominal aortic dissecting aneurysms (cTAADA) is regarded as one of the most challenging procedures in the field of vascular surgery. For nearly six decades, open repair predominantly utilizing prosthetic grafts has been the treatment of choice for cTAADA. With advances in minimally invasive endovascular technologies, two novel surgical approaches have emerged: total endovascular stent-graft repair and hybrid procedures combining retrograde debranching of visceral arteries with endovascular stent-graft repair (abbreviated as hybrid procedure). Although total endovascular stent-graft repair offers reduced trauma and quicker recovery, limitations persist in clinical application due to hostile anatomical requirements of the aorta, high costs, and the lack of universally available stent-graft products. Hybrid repair, integrating the minimally invasive ethos of endovascular repair with visceral artery debranching techniques, has increasingly become a significant surgical modality for managing thoracoabdominal aneurysms, especially in cases unsuitable for open surgery or total endovascular treatment due to anatomical constraints such as aortic tortuosity or narrow true lumens in dissections. Recent enhancements in hybrid surgical approaches include ongoing optimization of visceral artery reconstruction strategies based on hemodynamic analyses, and exploration of the comparative benefits of staged versus concurrent surgical interventions.
As an important means of treating heart failure (HF), cardiac assist device has been widely used in clinic. This paper reviews the application status, existing problems and future development trend of cardiac assist devices, including the classification of cardiac assist devices, representative research achievements and indications of the assist devices. It also summarizes the biomechanical indexes of the heart and the new approaches and methods for treating heart failure, as well as the hemodynamic studies of cardiac assist devices in recent years. The research findings provide references for further optimization of cardiac assist device structure and clinical application of the device.