scholarly journals Left Ventricular Flow Analysis: Recent Advances in Numerical Methods and Applications in Cardiac Ultrasound

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Iman Borazjani ◽  
John Westerdale ◽  
Eileen M. McMahon ◽  
Prathish K. Rajaraman ◽  
Jeffrey J. Heys ◽  
...  
Keyword(s):  
Heart Valves ◽  
Flow Analysis ◽  
Systemic Circulation ◽  
Left Ventricular ◽  
The Body ◽  
Patient Specific ◽  
Future Research ◽  
Prognostic Information ◽  
Flow Measurements ◽  
Recent Advances

The left ventricle (LV) pumps oxygenated blood from the lungs to the rest of the body through systemic circulation. The efficiency of such a pumping function is dependent on blood flow within the LV chamber. It is therefore crucial to accurately characterize LV hemodynamics. Improved understanding of LV hemodynamics is expected to provide important clinical diagnostic and prognostic information. We review the recent advances in numerical and experimental methods for characterizing LV flows and focus on analysis of intraventricular flow fields by echocardiographic particle image velocimetry (echo-PIV), due to its potential for broad and practical utility. Future research directions to advance patient-specific LV simulations include development of methods capable of resolving heart valves, higher temporal resolution, automated generation of three-dimensional (3D) geometry, and incorporating actual flow measurements into the numerical solution of the 3D cardiovascular fluid dynamics.

scholarly journals Recent Advances in the Treatment of ST-Segment Elevation Myocardial Infarction

Scientifica ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Mun K. Hong
Keyword(s):  
Myocardial Infarction ◽  
Primary Angioplasty ◽  
Left Ventricular ◽  
Pharmacologic Therapy ◽  
Future Research ◽  
St Segment Elevation ◽  
Segment Elevation Myocardial Infarction ◽  
Recent Advances ◽  
St Segment ◽  
Artery Disease

ST-segment elevation myocardial infarction (STEMI) represents the most urgent condition for patients with coronary artery disease. Prompt diagnosis and therapy, mainly with primary angioplasty using stents, are important in improving not only acute survival but also long-term prognosis. Recent advances in angioplasty devices, including manual aspiration catheters and drug-eluting stents, and pharmacologic therapy, such as potent antiplatelet and anticoagulant agents, have significantly enhanced the acute outcome for these patients. Continuing efforts to educate the public and to decrease the door-to-balloon time are essential to further improve the outcome for these high-risk patients. Future research to normalize the left ventricular function by autologous stem cell therapy may also contribute to the quality of life and longevity of the patients surviving STEMI.

3D Reconstruction of the Left Ventricle From Four Echocardiographic Projections

2014 ◽  
Author(s):  
Navaneetha Krishnan Rajan ◽  
Zeying Song ◽  
Kenneth R. Hoffmann ◽  
Marek Belohlavek ◽  
Eileen M. McMahon ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Three Dimensional ◽  
Image Data ◽  
Left Ventricular ◽  
The Body ◽  
Patient Specific ◽  
Immersed Boundary ◽  
Cross Sectional ◽  
Standard Format ◽  
Automated Method

The left ventricle (LV) of a human heart receives oxygenated blood from the lungs and pumps it throughout the body via the aortic valve. Characterizing the LV geometry, its motion, and the ventricular flow is critical in assessing the heart’s health. An automated method has been developed in this work to generate a three-dimensional (3D) model of the LV from multiple-axis echocardiography (echo). Image data from three long-axis sections and a basal section is processed to compute spatial nodes on the LV surface. The generated surfaces are output in a standard format such that it can be imported into the curvilinear-immersed boundary (CURVIB) framework for numerical simulation of the flow inside the LV. The 3D LV model can be used for better understanding of the ventricular motion and the simulation framework provides a powerful tool for studying left ventricular flows on a patient specific basis. Future work would incorporate data from additional cross-sectional images.

scholarly journals Computational Analysis of Self-Expanding and Balloon-Expandable Transcatheter Heart Valves

Biomechanics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 43-52
Author(s):  
Salvatore Pasta ◽  
Caterina Gandolfo
Keyword(s):  
Aortic Valve ◽  
Heart Valves ◽  
Numerical Study ◽  
Flow Analysis ◽  
Patient Specific ◽  
Area At Risk ◽  
Virtual Planning ◽  
Local Maxima ◽  
Transcatheter Aortic Valve ◽  
Transcatheter Heart Valve

Bicuspid aortic valve (BAV) patients are usually excluded from transcatheter aortic valve implantation (TAVI) as this valve anatomy likely leads to oval expansion. This study presents a numerical study of TAVI using both self-expanding and balloon expandable transcatheter heart valve (THV) in bicuspid patients with severe stenosis. The simulation framework included a patient-specific anatomy of the aortic root, calcifications and BAV leaflets extracted from medical imaging analysis as well as a realistic crimping and deployment of the THV. Tissue stress analysis highlighted local maxima in the contact area between the inner aortic lumen and the THV stent frame. Flow analysis based on the smoothed particle hydrodynamics (SPH) technique displayed the area at risk of paravalvular leakage (PVL). These findings provide insights on the TAVI in BAV and thus represents a further step towards the use of in-silico for the virtual planning of TAVI, aiming at improving not only the efficacy of the implantation but also the exploration of borderline anatomy as the case of TAVI in BAVs.

Breast Milk Stem Cell Survival in Neonate's Gut, Entery into Neonate Circulation and Adaption by the Body

2020 ◽  
Vol 15 (2) ◽  
pp. 98-101 ◽  
Author(s):  
Amit Ghosh
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Breast Milk ◽  
Systemic Circulation ◽  
The Body ◽  
Future Research ◽  
Human Breast Milk ◽  
Human Breast ◽  
Cell Therapies ◽  
Therapeutic Uses

: The stem cell exchange during pregnancy is thought to remain chimeras for life. Few studies recently revealed that maternal transfer of viable stem cells to the offspring continues even after birth during breastfeeding. Some of these stem cells are likely to be integrated into different organs (brain, blood, kidneys, and pancreas) including neurons and insulin-producing cells in the pancreas to become functional cells. This finding opens a new avenue for research on therapeutic uses of breast milk- derived stem cells. : Recently Dr. Foteini Hassiotou used glowing mice, which were genetically modified to express a gene called tdTomato that causes cells to appear red under fluorescence light. These mice were mated, and their babies were swapped with the pups of another, unmodified mother mouse. The new pups suckled the modified mouse and, as a result, obtained glowing red stem cells from breast milk. The study has never been replicated in humans, so it is not clear yet if the findings apply to humans as in the case of mice. However, the results of the study are the jumping-off points for future research on human breast milk stem cells and their possible application in stem cell therapies. Additional studies are necessary to understand the passage of human breast milk stem cells through the neonate’s GI tract, and passage to the systemic circulation.

scholarly journals From 4D Medical Images (CT, MRI, and Ultrasound) to 4D Structured Mesh Models of the Left Ventricular Endocardium for Patient-Specific Simulations

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Federico Canè ◽  
Benedict Verhegghe ◽  
Matthieu De Beule ◽  
Philippe B. Bertrand ◽  
Rob J. Van der Geest ◽  
...  
Keyword(s):  
Medical Images ◽  
Left Ventricular ◽  
Moving Boundaries ◽  
Patient Specific ◽  
Diagnostic Tools ◽  
Future Research ◽  
Ct Reconstruction ◽  
Cfd Simulations ◽  
High Quality ◽  
Mesh Models

With cardiovascular disease (CVD) remaining the primary cause of death worldwide, early detection of CVDs becomes essential. The intracardiac flow is an important component of ventricular function, motion kinetics, wash-out of ventricular chambers, and ventricular energetics. Coupling between Computational Fluid Dynamics (CFD) simulations and medical images can play a fundamental role in terms of patient-specific diagnostic tools. From a technical perspective, CFD simulations with moving boundaries could easily lead to negative volumes errors and the sudden failure of the simulation. The generation of high-quality 4D meshes (3D in space + time) with 1-to-1 vertex becomes essential to perform a CFD simulation with moving boundaries. In this context, we developed a semiautomatic morphing tool able to create 4D high-quality structured meshes starting from a segmented 4D dataset. To prove the versatility and efficiency, the method was tested on three different 4D datasets (Ultrasound, MRI, and CT) by evaluating the quality and accuracy of the resulting 4D meshes. Furthermore, an estimation of some physiological quantities is accomplished for the 4D CT reconstruction. Future research will aim at extending the region of interest, further automation of the meshing algorithm, and generating structured hexahedral mesh models both for the blood and myocardial volume.

Gut microbiome a promising target for management of respiratory diseases

2020 ◽  
Vol 477 (14) ◽  
pp. 2679-2696
Author(s):  
Riddhi Trivedi ◽  
Kalyani Barve
Keyword(s):  
Respiratory Diseases ◽  
New Technology ◽  
Bacterial Flora ◽  
Systemic Circulation ◽  
The Body ◽  
Lung Pathology ◽  
Promising Target ◽  
Current Therapies ◽  
Intestinal Microbial Flora ◽  
On Chip

The intestinal microbial flora has risen to be one of the important etiological factors in the development of diseases like colorectal cancer, obesity, diabetes, inflammatory bowel disease, anxiety and Parkinson's. The emergence of the association between bacterial flora and lungs led to the discovery of the gut–lung axis. Dysbiosis of several species of colonic bacteria such as Firmicutes and Bacteroidetes and transfer of these bacteria from gut to lungs via lymphatic and systemic circulation are associated with several respiratory diseases such as lung cancer, asthma, tuberculosis, cystic fibrosis, etc. Current therapies for dysbiosis include use of probiotics, prebiotics and synbiotics to restore the balance between various species of beneficial bacteria. Various approaches like nanotechnology and microencapsulation have been explored to increase the permeability and viability of probiotics in the body. The need of the day is comprehensive study of mechanisms behind dysbiosis, translocation of microbiota from gut to lung through various channels and new technology for evaluating treatment to correct this dysbiosis which in turn can be used to manage various respiratory diseases. Microfluidics and organ on chip model are emerging technologies that can satisfy these needs. This review gives an overview of colonic commensals in lung pathology and novel systems that help in alleviating symptoms of lung diseases. We have also hypothesized new models to help in understanding bacterial pathways involved in the gut–lung axis as well as act as a futuristic approach in finding treatment of respiratory diseases caused by dysbiosis.

Clinical and Experimental Analysis of 201Thallium Uptake of the Heart

1978 ◽  
Vol 17 (04) ◽  
pp. 142-148
Author(s):  
U. Büll ◽  
S. Bürger ◽  
B. E. Strauer
Keyword(s):  
Oxygen Consumption ◽  
Left Ventricle ◽  
Muscle Mass ◽  
Myocardial Oxygen Consumption ◽  
Animal Experiments ◽  
Left Ventricular ◽  
Left Ventricular Wall ◽  
Ventricular Wall ◽  
Flow Measurements ◽  
Myocardial Flow

Studies were carried out in order to determine the factors influencing myocardial 201T1 uptake. A total of 158 patients was examined with regard to both 201T1 uptake and the assessment of left ventricular and coronary function (e. g. quantitative ventriculography, coronary arteriography, coronary blood flow measurements). Moreover, 42 animal experiments (closed chest cat) were performed. The results demonstrate that:1) 201T1 uptake in the normal and hypertrophied human heart is linearly correlated with the muscle mass of the left ventricle (LVMM);2) 201T1 uptake is enhanced in the inner (subendocardial) layer and is decreased in the outer (subepicardial) layer of the left ventricular wall. The 201T1 uptake of the right ventricle is 40% lower in comparison to the left ventricle;3) the basic correlation between 201T1 uptake and LVMM is influenced by alterations of both myocardial flow and myocardial oxygen consumption; and4) inotropic interventions (isoproterenol, calcium, norepinephrine) as well as coronary dilatation (dipyridamole) may considerably augment 201T1 uptake in accordance with changes in myocardial oxygen consumption and/or myocardial flow.It is concluded that myocardial 201T1 uptake is determined by multiple factors. The major determinants have been shown to include (i) muscle mass, (ii) myocardial flow and (iii) myocardial oxygen consumption. The clinical data obtained from patient groups with normal ventricular function, with coronary artery disease, with left ventricular wall motion abnormalities and with different degree of left ventricular hypertrophy are correlated with quantitated myocardial 201T1 uptake.

Cardiac Resynchronisation Therapy – Evolving Strategies to Enhance Response

2010 ◽  
Vol 6 (1) ◽  
pp. 83
Author(s):  
Jagmeet P Singh ◽  
Keyword(s):  
Heart Failure ◽  
Systolic Heart Failure ◽  
Cardiac Resynchronisation Therapy ◽  
Left Ventricular ◽  
Patient Specific ◽  
Cardiac Resynchronisation ◽  
Clinical Benefits ◽  
Pacing Lead ◽  
Resynchronisation Therapy ◽  
Physiological Impact

Cardiac resynchronisation therapy (CRT) has gained widespread acceptance as a safe and effective therapeutic strategy for congestive heart failure (CHF) refractory to optimal medical therapy. The use of implantable devices has substantially altered the natural history of systolic heart failure. These devices exert their physiological impact through ventricular remodelling, associated with a reduction in left ventricular (LV) volumes and an improvement in ejection fraction (EF). Several prospective randomised studies have shown that this in turn translates into long-term clinical benefits such as improved quality of life, increased functional capacity and reduction in hospitalisation for heart failure and overall mortality. Despite these obvious benefits, there remain more than a few unresolved concerns, the most important being that up to one-third of patients treated with CRT do not derive any detectable benefit. There are several determinants of successful delivery and response to CRT, including selecting the appropriate patient, patient-specific optimal LV pacing lead placement and appropriate post-implant device care and follow-up. This article highlights the importance of collectively working on all of these aspects of CRT to enhance and maximise response.

Development of Solid-Self Micron Emulsifying Drug Delivery Systems

2013 ◽  
Vol 6 (2) ◽  
pp. 2014-2021
Author(s):  
Preethi Sudheer ◽  
Koushik Y ◽  
Satish P ◽  
Uma Shankar M S ◽  
R S Thakur
Keyword(s):  
Drug Delivery ◽  
Systemic Circulation ◽  
Water Soluble ◽  
Future Research ◽  
Steady Increase ◽  
Liquid Form ◽  
Lipophilic Compounds ◽  
Modern Drug ◽  
Pharmaceutical Scientist ◽  
Pharmacologically Active

As a consequence of modern drug discovery techniques, there has been a steady increase in the number of new pharmacologically active lipophilic compounds that are poorly water soluble and solubility is one of the most important parameter to achieve desired concentration of drug in systemic circulation for therapeutic response. It is a great challenge for pharmaceutical scientist to convert those molecules into orally administered formulation with sufficient bioavailability.  Among the several approaches to improve oral bioavailability of these molecules, Self-micron emulsifying drug delivery system (SMEDDS) is one of the approaches usually used to improve the bioavailability of hydrophobic drugs. However, conventional SMEDDS are mostly prepared in a liquid form, which can have several disadvantages. Accordingly, solid SMEDDS (S-SMEDDS) prepared by solidification of liquid/semisolid self-micron emulsifying (SME) ingredients into powders have gained popularity. This article provides an overview of the recent advancements in S-SMEDDS such as methodology, techniques and future research directions.

Scaffolds for Drug Delivery in Tissue Engineering

2008 ◽  
Vol 1 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Vikas V. Gaikwad ◽  
Abasaheb B. Patil ◽  
Madhuri V. Gaikwad
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Heart Diseases ◽  
Cartilage Regeneration ◽  
Tissue Growth ◽  
The Body ◽  
Patient Specific ◽  
In Situ Gel ◽  
Heart Muscle Cells

Scaffolds are used for drug delivery in tissue engineering as this system is a highly porous structure to allow tissue growth.  Although several tissues in the body can regenerate, other tissue such as heart muscles and nerves lack regeneration in adults. However, these can be regenerated by supplying the cells generated using tissue engineering from outside. For instance, in many heart diseases, there is need for heart valve transplantation and unfortunately, within 10 years of initial valve replacement, 50–60% of patients will experience prosthesis associated problems requiring reoperation. This could be avoided by transplantation of heart muscle cells that can regenerate. Delivery of these cells to the respective tissues is not an easy task and this could be done with the help of scaffolds. In situ gel forming scaffolds can also be used for the bone and cartilage regeneration. They can be injected anywhere and can take the shape of a tissue defect, avoiding the need for patient specific scaffold prefabrication and they also have other advantages. Scaffolds are prepared by biodegradable material that result in minimal immune and inflammatory response. Some of the very important issues regarding scaffolds as drug delivery systems is reviewed in this article.

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