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Differential Impact Of Blood Pressure Control Targets On Epicardial Coronary Flow After Transcatheter Aortic Valve Replacement, Brennan Vogl, Alejandra Chavez-Ponce, Adam Wentworth, Eric Erie, Pradeep Yadav, Vinod H. Thourani, Lakshmi Prasad Dasi, Brian Lindman, Mohamad Alkhouli, Hoda Hatoum

Michigan Tech Publications, Part 2

Background: The cause for the association between increased cardiovascular mortality rates and lower blood pressure (BP) after aortic valve replacement (AVR) is unclear. This study aims to assess how the epicardial coronary flow (ECF) after AVR varies as BP levels are changed in the presence of a right coronary lesion. Methods: The hemodynamics of a 3D printed aortic root model with a SAPIEN 3 26 deployed were evaluated in an in vitro left heart simulator under a range of varying systolic blood pressure (SBP) and diastolic blood pressure (DBP). ECF and the flow ratio index were calculated. Flow index value …

The Effects Of Mechanical Strain On Vascular Calcification And The Canonical Wnt Pathway, Hannah E. Douglas

Theses and Dissertations

Cardiovascular disease is a significant health crisis, representing 32% of deaths worldwide in 2019. Vascular calcification (VC), a major contributor to cardiovascular disease, is a regulated biomineralization process whose exact mechanisms are unknown. Additionally, vascular smooth muscle cells (VSMCs) significantly contribute to VC by undergoing a phenotypic switch and differentiating into osteoblast-like cells. When factors like hypertension cause disturbed laminar flow in the body’s vasculature, the mechanical stress promotes the phenotypic switch and calcification of VSMCs via mechanotransduction. VC is also induced by the Wnt pathway, which is activated via mineral imbalance and mechanical stimulation. However, the exact mechanisms behind …

Medical Foods For Lowering Homocysteine In Hypertensive Patients, Merrill F. Elias, Craig J. Brown

Maine-Syracuse Longitudinal Papers

In a recent commentary, Elias and Brown review the history of skepticism about the value of homocysteine for preventing hypertension and stroke. They argue that this skepticism is not supported by recent literature. This paper was stimulated by a recent comprehensive review of the literature on this topic by Smith and Refsum. Prior to these papers, a commentary and review by Skeete and DiPette provided evidence for the value of homocysteine-lowering in the treatment of hypertension. Elias and Brown supported this conclusion. Both papers emphasized that more work is needed to clarify the beneficial effects of lowering homocysteine.

Elias and …

New Evidence For Homocysteine Lowering For Management Of Treatment-Resistant Hypertension, Merrill F. Elias, Craig J. Brown

Maine-Syracuse Longitudinal Papers

Treatment-resistant hypertension is a topic of great importance and the subject of editorial comments in the American Journal of Hypertension. Homocysteine is an intermediate compound in the vitamin regulated One Carbon Methylation pathway which affects glutathione, methionine, and nitric oxide metabolism. Elevated homocysteine, triggered by genetic mutations or insufficient body stores of active vitamins B6, B12, folate, riboflavin, indicates oxidative stress and is associated with impaired nitric oxide synthesis causing small vessel vasoconstriction in the central nervous system. High homocysteine (defined later) is also a risk factor for hypertension.

Development Of A Bipolar Radiofrequency Ablation Device For Renal Denervation, Noel Perez

USF Tampa Graduate Theses and Dissertations

The American Heart Association (AHA) reported in March 2020, hypertension (HT) is a major risk factor for cardiovascular diseases and heart stroke. Resistant hypertension (RH) is a subset of HT and affects 11-16% of hypertensive patients. RH is diagnosed when a patient cannot achieve blood pressure control despite taking three or more medications and is a serious clinical management challenge.

Renal denervation (RD) using radiofrequency (RF) ablation is an accepted form of RH therapy. RD devices are typically delivered through femoral access into the renal artery with the assistance of a standard guided sheath. In the European Union (EU), the …

Factors Associated With Mutations: Their Matching Rates To Cardiovascular And Neurological Diseases, Hannah B. Lucas, Ian Mcknight, Regan Raines, Abdullah Hijazi, Christoph Hart, Chan Lee, Do-Gyoon Kim, Wei Li, Peter H. U. Lee, Joon W. Shim

Biomedical Engineering Faculty Research

Monogenic hypertension is rare and caused by genetic mutations, but whether factors associated with mutations are disease-specific remains uncertain. Given two factors associated with high mutation rates, we tested how many previously known genes match with (i) proximity to telomeres or (ii) high adenine and thymine content in cardiovascular diseases (CVDs) related to vascular stiffening. We extracted genomic information using a genome data viewer. In human chromosomes, 64 of 79 genetic loci involving >25 rare mutations and single nucleotide polymorphisms satisfied (i) or (ii), resulting in an 81% matching rate. However, this high matching rate was no longer observed as …

Vascular Endothelial Dysfunction And Effects On Arterial Wall Microstructure, Jeffrey Thomas Rodgers

Theses and Dissertations

Vascular endothelial cell dysfunction (ECD) is a disease characterized by the inability of the vascular endothelial cells to transmit signaling molecules, namely nitric oxide (NO), in response to changes in blood flow rate. This disease is shown to be incident in the onset of more severe vascular disease such as hypertension, atherosclerosis, and heart failure. Long-term ECD is shown to cause long-term remodeling such as decreased flow-mediated dilation, increased pulse-wave velocity, intimal-medial thickening, and increased wall stiffness due to collagen deposition. We used second harmonic generation (SHG) microscopy to analyze this change in the collagen microstructure of the arterial extracellular …

Human Errors In Automated Office Blood Pressure Measurement, Merrill F. Elias, Amanda L. Goodell

Maine-Syracuse Longitudinal Papers

In this review of the literature and commentary, we examine the literature on automated blood pressure (BP) measurements in the office and clinic. Our purpose is to revisit issues as to the pros and cons of automated BP measurement published in Hypertension in June 2020 and to identify areas needing additional research. Despite initial reservations about automated BP, it is here to stay. A number of experts suggest that human error will be reduced when we move from the more complex skills required by aneroid sphygmomanometer measurement to the fewer skills and steps required by automated BP measurement. Our review …

The Sars-Cov-2 Spike Protein Alters Barrier Function In 2d Static And 3d Microfluidic In-Vitro Models Of The Human Blood-Brain Barrier., Tetyana P Buzhdygan, Brandon J Deore, Abigail Baldwin-Leclair, Trent A Bullock, Hannah M Mcgary, Jana A Khan, Roshanak Razmpour, Jonathan F Hale, Peter Galie, Raghava Potula, Allison M Andrews, Servio H Ramirez

Henry M. Rowan College of Engineering Faculty Scholarship

As researchers across the globe have focused their attention on understanding SARS-CoV-2, the picture that is emerging is that of a virus that has serious effects on the vasculature in multiple organ systems including the cerebral vasculature. Observed effects on the central nervous system include neurological symptoms (headache, nausea, dizziness), fatal microclot formation and in rare cases encephalitis. However, our understanding of how the virus causes these mild to severe neurological symptoms and how the cerebral vasculature is impacted remains unclear. Thus, the results presented in this report explored whether deleterious outcomes from the SARS-CoV-2 viral spike protein on primary …

Distinct White Matter Changes Associated With Cerebrospinal Fluid Amyloid-Β1-42 And Hypertension, Omar M. Al-Janabi, Christopher A. Brown, Ahmed A. Bahrani, Erin L. Abner, Justin M. Barber, Brian T. Gold, Larry B. Goldstein, Richard R. Murphy, Peter T. Nelson, Nathan F. Johnson, Leslie M. Shaw, Charles D. Smith, John Q. Trojanowski, Donna M. Wilcock, Gregory A. Jicha

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Alzheimer's disease (AD) pathology and hypertension (HTN) are risk factors for development of white matter (WM) alterations and might be independently associated with these alterations in older adults.

OBJECTIVE: To evaluate the independent and synergistic effects of HTN and AD pathology on WM alterations.

METHODS: Clinical measures of cerebrovascular disease risk were collected from 62 participants in University of Kentucky Alzheimer's Disease Center studies who also had cerebrospinal fluid (CSF) sampling and MRI brain scans. CSF Aβ_1-42 levels were measured as a marker of AD, and fluid-attenuated inversion recovery imaging and diffusion tensor imaging were obtained to assess …

Ambulatory Systolic Blood Pressure And Obesity Are Independently Associated With Left Ventricular Hypertrophic Remodeling In Children, Linyuan Jing, Christopher D. Nevius, Cassi M. Friday, Jonathan D. Suever, Arichanah Pulenthiran, Abba Mejia-Spiegeler, H. Lester Kirchner, William J. Cochran, Gregory J. Wehner, Aftab S. Chishti, Christopher M. Haggerty, Brandon K. Fornwalt

Biomedical Engineering Faculty Publications

Background: Children with obesity have hypertrophic cardiac remodeling. Hypertension is common in pediatric obesity, and may independently contribute to hypertrophy. We hypothesized that both the degree of obesity and ambulatory blood pressure (ABP) would independently associate with measures of hypertrophic cardiac remodeling in children.

Methods: Children, aged 8–17 years, prospectively underwent cardiovascular magnetic resonance (CMR) and ABP monitoring. Left ventricular (LV) mass indexed to height^2.7(LVMI), myocardial thickness and end-diastolic volume were quantified from a 3D LV model reconstructed from cine balanced steady state free precession images. Categories of remodeling were determined based on cutoff values for LVMI and …

Systolic Orthostatic Hypotension Is Related To Lowered Cognitive Function: Findings From The Maine-Syracuse Longitudinal Study, Rachael V. Torres, Merrill Elias, Georgina E. Crichton, Gregory A. Dore, Adam Davey

Maine-Syracuse Longitudinal Papers

The aim of the present study was to examine the relationship between orthostatic changes in blood pressure (BP) and cognition, with consideration given to cardiovascular risk factors and lifestyle variables. The cross-sectional analysis included 961 community-dwelling participants of the Maine-Syracuse Longitudinal Study, for whom BP clinic measures (five sitting, five recumbent, and five standing) were obtained. Eighteen percent of participants had orthostatic hypotension (fall in systolic BP ≥20 mm Hg or diastolic BP ≥10 mm Hg upon standing) and 6% had orthostatic hypertension (rise in systolic BP ≥20 mm Hg). Orthostatic hypotension and hypertension defined using traditional criteria were unrelated …

Comparing Machine Learning And Logistic Regression Methods For Predicting Hypertension Using A Combination Of Gene Expression And Next-Generation Sequencing Data, Elizabeth Held, Joshua Cape, Nathan L. Tintle

Faculty Work Comprehensive List

Machine learning methods continue to show promise in the analysis of data from genetic association studies because of the high number of variables relative to the number of observations. However, few best practices exist for the application of these methods. We extend a recently proposed supervised machine learning approach for predicting disease risk by genotypes to be able to incorporate gene expression data and rare variants. We then apply 2 different versions of the approach (radial and linear support vector machines) to simulated data from Genetic Analysis Workshop 19 and compare performance to logistic regression. Method performance was not radically …

Gene Expression In Experimental Aortic Coarctation And Repair: Candidate Genes For Therapeutic Intervention?, John F. Ladisa Jr., Serdar Bozdag, Jessica Olson, Ramani Ramchandran, Judy R. Kersten, Thomas J. Eddinger

Biomedical Engineering Faculty Research and Publications

Coarctation of the aorta (CoA) is a constriction of the proximal descending thoracic aorta and is one of the most common congenital cardiovascular defects. Treatments for CoA improve life expectancy, but morbidity persists, particularly due to the development of chronic hypertension (HTN). Identifying the mechanisms of morbidity is difficult in humans due to confounding variables such as age at repair, follow-up duration, coarctation severity and concurrent anomalies. We previously developed an experimental model that replicates aortic pathology in humans with CoA without these confounding variables, and mimics correction at various times using dissolvable suture. Here we present the most comprehensive …

Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

A computational framework was implemented and validated to better understand the hypertensive artery remodeling in both geometric dimensions and material properties. Integrating the stress-modulated remodeling equations into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both arterial thickening and stiffening effects were captured and visualized. An adaptive material remodeling strategy combined with the element birth and death techniques for the geometrical growth were implemented. The numerically predicted remodeling results in terms of the wall thickness, inner diameter, and the ratio of elastin to collagen content of the artery were compared with and fine-tuned by …

Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

A computational framework was implemented and validated to better understand the hypertensive artery remodeling in both geometric dimensions and material properties. Integrating the stress-modulated remodeling equations into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both arterial thickening and stiffening effects were captured and visualized. An adaptive material remodeling strategy combined with the element birth and death techniques for the geometrical growth were implemented. The numerically predicted remodeling results in terms of the wall thickness, inner diameter, and the ratio of elastin to collagen content of the artery were compared with and fine-tuned by …

High Rates Of Uncontrolled Blood Pressure: Pulse Wave Velocity And Future Opportunities, Merrill Elias, Kevin Sullivan, Gregory A. Dore, Michael A. Robbins

Maine-Syracuse Longitudinal Papers

The recent commentary on high rates of uncontrolled blood pressure (BP) and opportunities for health care providers in this Journal prompted an examination of treated but uncontrolled BP in relation to pulse wave velocity (PWV) in the Maine Syracuse Longitudinal Study (MSLS). Cohen and Townsend noted that a Center for Disease Control analysis2 of National Health and Nutrition Examination Survey (NHANES) data (2003–2010) indicated that the presence of uncontrolled hypertension (≥140 mm Hg systolic and ≥90 mm Hg diastolic) in US adults was 53.5%. They further noted that approximately 45% of these individuals with uncontrolled hypertension were aware of their …

Effect Of Arginine And Oscillatory Ca2+ On Vascular Response Mediated Via Nitric Oxide Signaling In Normal And Salt Sensitive Hypertensive Rat Mesenteric Arterioles, Tushar V. Gadkari

FIU Electronic Theses and Dissertations

Hypertension, a major risk factor in the cardiovascular system, is characterized by an increase in the arterial blood pressure. High dietary sodium is linked to multiple cardiovascular disorders including hypertension. Salt sensitivity, a measure of how the blood pressure responds to salt intake is observed in more than 50% of the hypertension cases. Nitric Oxide (NO), as an endogenous vasodilator serves many important biological roles in the cardiovascular physiology including blood pressure regulation. The physiological concentrations for NO bioactivity are reported to be in 0-500 nM range. Notably, the vascular response to NO is highly regulated within a small concentration …

Md Mouse: Integrated Blood Pressure Device, Anand Shah, Jamila Mckenzie, Rex Weinstein, Noelle Nelson, Clayton Goertemiller

Intersections Fall 2020

Hypertension, or high blood pressure, is a public health concern due to both its pervasiveness and the significant risk of disability, stroke, or heart attack that can occur years after high blood pressure is detected. Furthermore, new pandemic statistics suggest that patients with hypertension experience greater health consequences of COVID-19, indicating that the condition is more circumstantially deadly. Occasional visits to a doctor's office, the most common method to measure blood pressure, only provide a snapshot of a person's blood pressure and are not an accurate characterization. This is because blood pressure can fluctuate based on daily changes to the …

Effects Of Hypertension And Aging On Vascular Smooth Muscle Cell Contribution To Reconstituted Aortic Tissue Stiffness, Nancy Lisa Sehgel

Theses

Aortic stiffness increases with hypertension and aging, and much of this increase has been thought to occur due to changes in the extracellular matrix. However, an increase in cell stiffness could also be important. To study the cellular contribution to aortic stiffness, a reconstituted aortic tissue model (composed of vascular smooth muscle cells (VSMCs) in a collagen matrix) was developed. VSMCs isolated from thoracic aortic samples of 5-week and 18-week old male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were passaged four times and then separately incubated in collagen for two days on a cylindrical mandrel. The resulting …

Computational Modeling Of Oxidative Stress: An Analysis Of Nad (P)H Effects On Nitric Oxide And Superoxide During Hypertension, Aaron Strobel

Biological and Agricultural Engineering Undergraduate Honors Theses

Nitric oxide (NO) is inactivated in the human body when exposed to superoxide (O2 -). This reaction forms peroxynitrite (ONOO-). Superoxide is produced in the cardiac system by several different ways, including NAD(P)H oxidase. Superoxide dismutase (SOD) breaks down superoxide into oxygen and hydrogen peroxide. This prevents superoxide from reacting with nitric oxide and allows normal function to take place. Superoxide and peroxynitrite are main contributors to vascular disease in the human body, in particular hypertension. Experiments have shown that there was an increase of superoxide production in spontaneously hypertensive rats (SHR) vs. age-matched Wistar Kyoto rats (WKY) that were …

Functional Interplay Between Subthreshold Ion Channels In Preautonomic Neurons Of The Hypothalamic Paraventricular Nucleus In Health And Disease Conditions, Patrick M. Sonner

Browse all Theses and Dissertations

Under normal conditions, blood pressure is tightly regulated through autonomic tonic and reflex mechanisms. However, when the set-point for blood pressure is chronically elevated, hypertension occurs. Hypertension if untreated can lead to further complications including heart failure, stroke and kidney failure. Elevated sympathetic outflow is known to contribute to the development and/or maintenance of hypertension, and while the hypothalamic paraventricular nucleus (PVN), a preautonomic center, has been implicated in the elevation of sympathetic activity during hypertension, the precise pathophysiological mechanisms underlying sympathoexcitation remain unclear. Subthreshold ion channels, including the A-type K ⁺(I _A) and the T-type Ca ^{2+ …}

Characterization Of Hypertension Through Multivariate Analysis Utilizing Linear And Nonlinear Methods, Diane L. Donnelly

Dissertations

Analysis of blood pressure by nonlinear methods is vastly underutilized in current research. As such, 24-hour ambulatory blood pressure data from a small cohort of borderline hypertensive and normotensive subjects were analyzed using linear and nonlinear methods. Data were collected and provided by researchers from Columbia University. The cohort size was twelve subjects, consisting of two groups of six each. Although disease state was known, group membership for individual subjects was not. Therefore, one aspect of this research was to separate the cohort, a-priori, into two distinct, evenly sized groups, based solely on analysis results. Separation was accomplished by the …

Lung Circulation Modeling: Status And Prospect, Anne V. Clough, Said H. Audi, Robert C. Molthen, Gary S. Krenz

Biomedical Engineering Faculty Research and Publications

Mathematical modeling has been used to interpret anatomical and physiological data obtained from metabolic and hemodynamic studies aimed at investigating structure-function relationships in the vasculature of the lung, and how these relationships are affected by lung injury and disease. The indicator dilution method was used to study the activity of redox processes within the lung. A steady-state model of the data was constructed and used to show that pulmonary endothelial cells may play an important role in reducing redox active compounds and that those reduction rates can be altered with oxidative stress induced by exposure to high oxygen environments. In …

The Influence Of Exercise On Oxygen Uptake In Mild Hypertension, Matthew Joseph Herban

Theses

The amount of oxygen used by muscle cells increase with exercise. The two body systems that influence the amount of oxygen delivered are the cardiovascular system and the pulmonary system. Two groups of patients were studied, those that were mildly hypertensive (but are not taking prescription medication for hypertension) and the control or normal group. The two groups exercised on a bicycle ergometer. Work rate was increased in steps (multiples of thirty watts) until anaerobic threshold (as measured by an ear oximeter) was reached. Heart rate, blood pressure, oxygen uptake and carbon dioxide production were measured during exercise. Their data …

Estimation Of Pulmonary Arterial Volume Changes In The Normal And Hypertensive Fawn-Hooded Rat From 3d Micro-Ct Data, Robert C. Molthen, Christian Wieholt, Steven Thomas Haworth, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

In the study of pulmonary vascular remodeling, much can be learned from observing the morphological changes undergone in the pulmonary arteries of the rat lung when exposed to chronic hypoxia or other challenges which elicit a remodeling response. Remodeling effects include thickening of vessel walls, and loss of wall compliance. Morphometric data can be used to localize the hemodynamic and functional consequences. We developed a CT imaging method for measuring the pulmonary arterial tree over a range of pressures in rat lungs. X-ray micro-focal isotropic volumetric imaging of the arterial tree in the intact rat lung provides detailed information on …

Quantification Of Pulmonary Arterial Wall Distensibility Using Parameters Extracted From Volumetric Micro-Ct Images, Roger H. Johnson, Kelly Lynn Karau, Robert C. Molthen, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

Stiffening, or loss of distensibility, of arterial vessel walls is among the manifestations of a number of vascular diseases including pulmonary arterial hypertension. We are attempting to quantify the mechanical properties of vessel walls of the pulmonary arterial tree using parameters derived from high-resolution volumetric x-ray CT images of rat lungs. The pulmonary arterial trees of the excised lungs are filled with a contrast agent. The lungs are imaged with arterial pressures spanning the physiological range. Vessel segment diameters are measured from the inlet to the periphery, and distensibilities calculated from diameters as a function of pressure. The method shows …

Characterization Of The Oscillometric Method For Measuring Indirect Blood Pressure, L A. Geddes, M Voelz, C Combs, D Reiner, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

In this study, human subjects and dogs were used to determine the ability of the oscillometric method to indicate systolic and diastolic pressure. In the human studies, the auscultatory method was used as the reference. In the animal studies, directly recorded blood pressure was used as the reference. The ability of the sudden increase in cuff pressure oscillations during cuff deflation to indicate systolic pressure was examined and found to overestimate systolic pressure slightly in man, but more in animals. Systolic pressure was encountered when the cuff pressure oscillations were about one half of their maximum amplitude. However, in both …

Anxiety And Depression In Young And Middle Aged Hypertensive And Normotensive Subjects, W. Gibson Wood, Merrill F. Elias, Norman R. Schultz, Clyde A. Pentz

Maine-Syracuse Longitudinal Papers

This study examined the effects of essential hypertension on measures of anxiety and depression for two age groups of hypertensive (free from hypertension-related pathology and/or cardiovascular disease) and normotensive subjects. Hypertensive subjects had significantly higher State Anxiety scores and Zung Depression scores than did normotensive subjects. These differences between the blood pressure groups were due largely to the scores of the younger hypertensive subjects. The results of the present study are consistent with previous results from our laboratory that have found that younger hypertensives differed (relative to controls) from middle aged hypertensives on measures, such as, symptoms reported on the …