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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
751

The Associated Risk Factors for Coronary Artery Calcium in Asymptomatic Individuals with and Without Diabetes in Rural Central Appalachia

Mamudu, Hadii M., Subedi, Pooja, Paul, Timir, Alamin, Ali E., Alamian, Arsham, Wang, Liang, Stewart, David, Jones, Antwan, Harirforoosh, Sam, Blackwell, Gerald, Budoff, Matthew 01 October 2018 (has links)
Aim To examine the risk factor of coronary artery calcium (CAC) in individuals with diabetes and those without diabetes in Central Appalachia. Methods Study population included 2479 asymptomatic participants who underwent CAC screening between August 2012 and November 2016. CAC score was classified into four categories [0 (no plaque), 1–99 (mild plaque), 100–399 (moderate plaque), and ≥400 (severe plaque)]. Multinomial logistic regression analyses were conducted to test the association between CAC and cardiovascular disease (CVD) risk factors among participants with diabetes, age and gender matched controls, and randomly selected controls. Results 13.6% of total participants had diabetes. Around 69%, 59.8%, and 57.7% of the participants with diabetes, matched controls, and randomly selected controls had CAC score ≥1, respectively. Participants with diabetes had higher prevalence of all CVD risk factors than controls. Among participants with diabetes, hypertension and physical inactivity increased the odds of CAC = 100–399, while among those without diabetes, hypertension and hypercholesteremia increased the odds of having CAC = 1–99 and CAC ≥ 400. Conclusion Half of study participants had subclinical atherosclerosis (i.e., CAC), and individuals with diabetes had higher CAC scores. This study suggests that individuals with diabetes in Central Appalachia might benefit from screening for CAC.
752

Déterminants du pronostic de la maladie coronarienne stable / Determinants of the prognosis of stable coronary artery disease

Sorbets, Emmanuel 18 September 2017 (has links)
Les patients coronariens stables ou stabilisés sont à haut risque d’évènements cardiovasculaires. Ils représentent une population hétérogène avec une présentation clinique, un terrain et un pronostic pouvant être extrêmement variables d’un patient à l’autre. Pourtant, d’après les recommandations internationales, tous doivent bénéficier d’une prise en charge relativement comparable basée sur des essais cliniques réalisés dans des sous-populations restreintes de patients stables et instables, pour la plupart anciens, et ne correspondant plus à la prise en charge actuelle des patients. Préciser les déterminants du pronostic de cette population, et notamment les stratégies thérapeutiques, est un enjeu majeur.Les antagonistes du système rénine-angiotensine (IEC/ARA2) font partie de l’arsenal médicamenteux de tout patient coronarien. Pourtant leur intérêt, en association aux antiagrégants plaquettaires et statines, est incertain chez les patients sans dysfonction ventriculaire gauche qui constituent un sous-groupe important parmi les patients stables.Le registre international REACH a évalué l’impact des IEC/ARA2 dans cette population avec 4 ans de suivi. La méthodologie statistique utilisée a été une analyse observationnelle avec ajustement ou avec appariement selon le score de propension. Il n’a pas été mis en évidence de bénéfice des IEC/ARA2 sur le critère de jugement principal composite associant décès cardiovasculaire – IDM – AVC, de même que sur le critère de jugement secondaire associant décès cardiovasculaire – IDM – AVC – Hospitalisation pour évènement athéro-thrombotique ou sur les critères tertiaires comprenant individuellement chacun des critères de jugement secondaire ainsi que sur la mortalité toute cause. Enfin il n’est pas ressorti non plus de bénéfice franc dans les sous-groupes d’analyse. Les résultats ont été concordants lorsque les analyses ont été réalisées pour les IEC seuls ou pour les ARA2 seuls, et ont été confortés par diverses analyses de sensibilité.Ces données méritent confirmation dans une cohorte indépendante. C’est l’un des objectifs du registre CLARIFY, registre de 32703 patients coronariens stables ou stabilisés, dont le suivi à 5 ans est terminé. Dans ce registre contemporain international, le taux global à 5 ans de mortalité toute cause a été de 7,9%, de mortalité non cardiovasculaire de 5% et de mortalité cardiovasculaire de 2,9%. Un évènement cardiovasculaire comprenant infarctus du myocarde (fatal ou non), angor instable, revascularisation coronaire par angioplastie ou pontage est survenu chez 15,9% des patients.Tout comme les IEC/ARA2, l’impact des bétabloquants dans la prise en charge du coronarien stable ou stabilisé, sans dysfonction ventriculaire est également controversé. Cette classe médicamenteuse est en cours d’évaluation dans CLARIFY. L’analyse tient compte du type de bétabloquant, de la dose prescrite, des éventuelles intolérances amenant à modifier leur utilisation, de la présence et de l’ancienneté d’un infarctus du myocarde et la fraction d’éjection ventriculaire gauche.CLARIFY a également pour objectif d’approfondir les déterminants du pronostic de la maladie coronarienne stable, avec une analyse spécifiquement focalisée sur la présence de symptômes angineux, d’ischémie myocardique et sur leur combinaison, en fonction de l’utilisation des méthodes de revascularisation myocardiques, pour mieux comprendre les mécanismes responsables des évènements cardiovasculaires et évoluer vers une prise en charge plus personnalisée. / Stable or stabilized coronary artery disease patients are at high risk for cardiovascular events. They represent a heterogeneous population. The clinical presentation, the context and the prognosis can be extremely variable from one patient to another. However, according to the international guidelines, those patients should be given a relatively comparable treatment based on clinical trials realized in restricted subpopulations of stable and unstable patients. Most of these trials are old, and no longer correspond to the current management. Specifying the determinants of the prognosis of this population, and in particular the therapeutic strategies, is a major challenge.The antagonist receptors of renin-angiotensin system (ACEI/ARB) are a part of the treatment of any coronary artery disease patient. Yet their interest in the prognosis of this population without left ventricular dysfunction in association with antiplatelet agents and statins is uncertain.The contemporary REACH registry has assessed the impact of ACEI/ARB in this population with a 4-year of follow-up. The statistical methodology used was based on the propensity score. After adjustment or matching with the propensity score, there was no benefit of ACEI/ARB on the primary endpoint of cardiovascular death - MI - stroke. No benefit was found on the secondary endpoint of cardiovascular death - MI - stroke - hospitalization for atherothrombotic events. No benefit was found on the tertiary criteria including individually each of the secondary endpoints and on any cause mortality. Finally,there was no clear benefit in the analyzes subgroups. These results were consistent when the analyzes were performed for ACEI alone or for ARB alone. They were also supported by sensitivity analyzes.These data should be confirmed or reversed in an independent cohort. This will be one of the many objectives of the CLARIFY registry, that enrolled 32,703 stable or stabilized coronary artery disease patients. The 5-year follow-up is complete. In this international contemporary registry, the overall 5-year rate of total mortality was 7.9%, non-cardiovascular mortality was 5% and cardiovascular mortality was 2.9%. A cardiovascular event including myocardial infarction (fatal or not), unstable angina, coronary revascularization by angioplasty or bypass surgery occured in 15.9% of patients.Like ACEI/ARB, the impact of betablockers on the management of stable or stabilized coronary artery disease without left ventricular dysfunction is also controversial. This drug class is being evaluated in CLARIFY. The analyzis takes into account the type of beta-blocker, the prescribed dose, any intolerance leading to changes in their use, the history of a myocardial infarction, and the left ventricular ejection fraction.CLARIFY will help to more define the determinants of the prognosis of stable coronary artery disease, with a more particular focus on symptomatic or not, ischemic or not, and revascularized or not, in order to better understand the mechanisms responsible for cardiovascular events, and evolve towards a more personalized and cost-effective care.
753

Toolkit for Implementation of Temporal Artery Thermometers for Neonates

Hargreaves, Linda 01 January 2017 (has links)
Accurate temperature assessment is essential in neonatal patients and allows for prompt recognition of illness. Temperature can be measured by rectum, which is subject to injury, axillary, which is time-consuming, and temporal artery, which is safe and fast. The purpose of this evidence-based practice quality improvement project was to create an educational toolkit for nurses teaching temporal artery thermometers for routine temperature measurement on neonates, to establish the content validity of the toolkit, and to make recommendations for implementation of the toolkit. The format applied was the Kellogg Logic Model that proceeded from the assumption, to planned work, and results. The theoretical framework was Roger's Diffusion of Innovations, which identifies champions as the initial change agents, helps engage the staff, and facilitates the change. The project consisted of a two-phase process. Phase 1 was the development of the toolkit contents by integrating the evidence and applying the framework in the context of working nurses. Phase 2 was the validation of the toolkit by expert nurses and educators with Item-CVI ranging from 0.80 to 1.00 and the scale-CVI at 0.98. The Toolkit for Implementation of Temporal Artery Thermometers for Neonates with three short video presentations was validated. The toolkit is shared on multiple webpages and is available to the public. Adopting the temporal artery thermometer for routine temperature measurement could be a new standard for temperature monitoring that is accurate and fast. Improved family satisfaction would result from a quicker temperature process and a less invasive method resulting in a more comfortable experience for their infant.
754

Virtual reality for the characterization of blood vessel to airway geometric relationships

Abdelraouf, Mostafa 01 January 2018 (has links)
An increase in the cross-sectional area (CSA) of the pulmonary arteries has been implicated in the progression of emphysema in COPD patients. Standardization of vessel size requires matching segments of the airway with their corresponding blood vessels. Automated matching is still error-prone, and manual matching by sifting through 2D slices is tedious and time-consuming. We propose a virtual reality (VR) system for the visualization of the airway and the vascular tree as a means of streamlining the verification of appropriate airway/vascular segment pairs selected for quantitation of arterial CSAs. In this work, we outline the technical specifications and design considerations and challenges for such system; we also compare user's performance on the proposed system with the conventional 2D method.
755

Patientinformation vid en kranskärlsoperation / Information for patients undergoing coronary artery bypass

Ahlin, Carola, Bengtsson, Irén, Nilsson, Lisbeth January 2010 (has links)
<p>Kranskärlsoperationen är för patienten en stor händelse som leder till många frågor och funderingar. Tidigare forskning har visat att patienter som genomgått en ranskärlsoperation har stort behov av information. Vårt syfte med studien var att beskriva informationen vid en kranskärlsoperation. Studien gjordes som en itteraturstudie. Resultatet av studien utföll i tre kategorier, informationsmetoder, vad informationen innehöll samt olika faktorer som påverkade patientinformationen. Information gavs skriftligt, muntligt, som videofilm, med Internet eller av en patient som tidigare gjort en kranskärlsoperation, ofta i kombination med varandra. Vad patienten ville att informationen skulle innehålla varierade från person till person beroende på i vilken fas patienten befann sig, pre- eller postoperativt. Flera faktorer framkom som var av betydelse. Det var viktigt för patienterna att personalen tog sig tid att lyssna och svara på frågor och funderingar. Patienter med litet socialt nätverk hade större behov av information än andra med stort socialt nätverk. En annan betydelsefull sak var att patienterna lätt skulle kunna komma i kontakt med kompetent personal både innan operationen och efter utskrivningen. Slutsatsen av resultatet var att informationen bör vara individuellt anpassad utifrån varje patients behov. Fortsatt forskning behövs för utveckling av en god patientinformation kring patienternas upplevelse av olika sorters informationssätt, samt att utveckla kontakt med patienter som tidigare gjort en kranskärlsoperation</p> / <p>Coronary artery bypass is for the patient a major event leading to many questions and concerns. Previous research has shown that patients who have undergone coronary artery bypass have great needs of information. Our aim of this study was to describe information before and after a coronary artery bypass. The study was done as a literature review. The results of the study were distributed into three categories, information methods, information content and the various factors that affect patient information. Information was given in writing, orally, by video, by Internet or by a patient previously undergoing a coronary artery surgery, usually in combination with each other. What the patient wanted the information should contain varied from person to person depending on what stage the patient was, pre- or postoperatively. Several factors emerged that were relevant. It was important for the patients that the staff took the time to listen and respond to questions and concerns. Patients with small social networks had a greater need for information than others with larger social network. Another important thing was that patients could easily get in touch with competent personnel both before surgery and after discharge. The conclusion of the result was that the information should be individualized based on each patient's needs. Continued research is needed to develop good patient information on patients' experience of different types of information means, and to develop contact with patients who have previously done a coronary artery bypass.</p>
756

α<sub>1</sub>- and α<sub>2</sub>-Adrenoceptors in the Eye : Pharmacological and Functional Characterization

Wikberg-Matsson, Anna January 2001 (has links)
<p>α<sub>1</sub>- and α<sub>2</sub>-Adrenoceptors are involved in various physiological events in the eye: blood flow regulation, aqueous humor dynamics and pupil regulation. The α<sub>1</sub>- and α<sub>2</sub>-adrenoceptors can be further subdivided into six subtypes (α<sub>1A</sub>, α<sub>1B</sub>, α<sub>1D</sub>, α<sub>2A</sub> , α<sub>2B</sub>, and α<sub>2C</sub> ). Currently available α1- and α<sub>2</sub>-adrenergic drugs are not selective for the different subtypes and some ocular adrenergics have undesirable side-effects, both local and systemic. A better understanding of the subtype distribution in the eye would be useful when designing new drugs with greater efficacy and fewer adverse effects; this applies especially to the treatment of glaucoma. The purpose of the thesis was therefore to identify and localize the different subtypes of α<sub>1</sub>- and α<sub>2</sub>-adrenoceptors in the eye. </p><p>The identities of the α<sub>1</sub>-adrenoceptor subtypes were studied in various parts of pig and albino rabbit eyes by radioligand binding. In the pig retina and in the albino rabbit iris, ciliary body and retina, mixed populations of α<sub>1A</sub>- and α<sub>1B</sub>-adrenoceptors were localized. In the rabbit choroid only the α<sub>1A</sub>-adrenoceptor subtype was detected. </p><p>The α<sub>2</sub>-adrenoceptor subtypes were also characterized by radioligand binding, in different parts of the pig eye. In the iris, ciliary body and choroid, only α<sub>2A</sub>-adrenoceptors were localized, while in the retina, mostly α<sub>2A</sub>-adrenoceptors and a minor population of α<sub>2C</sub>-adrenoceptors were identified. High densities of α<sub>2A</sub>-adrenoceptors were found in the ciliary body and choroid.</p><p>The effect of α<sub>2</sub>-adrenoceptor agonists on the porcine ciliary artery was studied on a small-vessel myograph. α<sub>2</sub>-Adrenoceptor agonists proved to be potent vasoconstrictors in the porcine ciliary artery and it was found that the vasoconstriction induced by brimonidine was mediated by the α<sub>A</sub>-adrenoceptor.</p>
757

Transesophageal Echocardiography in Patients Undergoing Elective Coronary Artery Bypass Surgery

Palmgren, Ingrid January 2002 (has links)
<p>Transesophageal echocardiography (TEE) has become a useful tool in monitoring the heart in patients during open-heart surgery. This study was undertaken to evaluate whether it is feasible to use TEE to assess left ventricular myocardial viability in anesthetized patients scheduled for coronary artery bypass grafting (CABG).</p><p>A total of 84 patients were studied. To test myocardial viability, TEE and a low-dose dobutamine stress regimen were used. Echocardiographic data were analyzed off-line using a visual or semiautomatic analysis of segmental left ventricular wall motion (LVWM). Visual assessment was performed by readers blinded to the sequence of events. The agreement between readers in visual analysis of segmental LVWM in the transgastric short-axis view was 73% or higher. Segmental LVWM assessed by TEE was compared to hemodynamic data obtained by thermodilution pulmonary artery catheter (PAC) and coronary angiographic data. Also, using the same low-dose dobutamine stress regimen, TEE findings in the anesthetized patient perioperatively were compared with preoperative transthoracic echocardiography (TTE) findings in the awake patient.</p><p>TEE was found to be feasible and adequate for testing left segmental ventricular viability. A concomitant increase in stroke volume assessed by PAC and decrease in LVWM-score assessed by TEE was found with dobutamine stimulation. Abnormal segmental LVWM corresponded to angiographically stenosed supplying coronary artery vessels. During dobutamine stimulation, 69% of the corresponding segments responded which is a sign of viability. The LVWM response to preoperative TTE and perioperative TEE dobutamine stress was comparable except for a significant difference in the apical segments.</p><p>This study showed that perioperative TEE dobutamine stress could be used to test left ventricular viability and was also a valuable supplement to PAC, angiography and TTE. The acquired knowledge is important and suggest that further development of transesophageal ultrasound technology is warranted.</p>
758

On Renal Artery Stenosis

Eklöf, Hampus January 2005 (has links)
<p>Renal artery stenosis (RAS) is a potentially curable cause of hypertension and azotemia. Besides intra-arterial renal angiography there are several non-invasive techniques utilized to diagnose patients with suspicion of renal artery stenosis. Removing the stenosis by revascularization to restore unobstructed blood flow to the kidney is known to improve and even cure hypertension/azotemia, but is associated with a significant complication rate. </p><p>To visualize renal arteries with x-ray techniques a contrast medium must be used. In a randomized, prospective study the complications of two types of contrast media (CO<sub>2</sub> and ioxaglate) were compared. CO<sub>2</sub> was not associated with acute nephropathy, but induced nausea and had lower attenuation differences compared to Ioxaglate. Acute nephropathy was related to the ioxaglate dose and the risk was evident even at very low doses if the patients were azotemic with creatinine clearance <40 ml/min. </p><p>Evaluating patients for clinically relevant renal artery stenosis can be done utilizing several non-invasive techniques. MRA was retrospectively evaluated and shown to be accurate in detecting hemodynamically significant RAS. In a prospective study of 58 patients, evaluated with four methods for renal artery stenosis, it was shown that MRA and CTA were significantly better than ultrasonography and captopril renography in detecting hemodynamically significant RAS. The standard of reference was trans-stenotic pressure gradient measurement, defining a stenosis as significant at a gradient of ≥15 mmHg. The discrepancies were mainly found in the presence of borderline stenosis.</p><p>The outcome of percutaneous revascularization procedures showed a technical success rate of 95%, clinical benefit in 63% of treated patients, 30-day mortality 1.5% and major complication rate of 13%. The major complication rate for patients with baseline serum creatinine >300µmol/l was 32%. Our results compare favorably with published studies and guidelines.</p>
759

On contrast-enhanced magnetic resonance angiography of the aortoiliac arteries

Wikström, Johan January 2001 (has links)
<p>In contrast-enhanced magnetic resonance angiography (CE-MRA),vascular signal is produced by the acquisition of a T1-weighted magnetic resonance imaging scan while the presence of a contrast agent induces a low T1 in blood. In this thesis,CE-MRA of the aortoiliac arteries was evaluated.Different contrast agents and techniques for synchronisation of the scan with the contrast bolus passage were assessed.</p><p>In 30 patients with clinically suspected iliac artery stenoses,contrast-enhanced magnetic resonance angiography was compared with duplex ultrasound scanning and digital subtraction x-ray angiography (DSA),with intraarterial pressure measurements as reference method. No statistically significant differences in sensitivity or specificity were observed between the techniques regarding the detection of hemodynamically significant iliac stenoses. The use of multiplanar reformats and source images in the MRA examinations was of value for the differentiation between high-grade stenoses and occlusions. With DSA as reference method, MRA had significantly higher sensitivity and specificity than duplex for the detection of ≥50% stenoses.</p><p>In fourteen patients examined with iliac artery MRA, differences in contrast arrival time of up to 7 s was observed between the aorta and the common femoral artery.A dual-station timing technique adjusting for this difference was found feasible. Compared with a fluoroscopically triggered technique (n=13),which is used in clinical rotine, the dual-station technique was more reliable for the visualisation of distal vessels.</p><p>In a clinical phase II study comparing different doses of t he contrast agent gadobenate dimeglumine for the enhancement of iliac artery MRA, a significant improvement in subjective diagnostic quality compared with time-of-flight MRA was found at all doses from 0.025 mmol/kg.An increasing trend with dose was observed up to a dose level of 0.05-0.1 mmol/kg.</p><p>In a phase I clinical study on the intravascular, iron oxide contrast agent NC100150 Injection, a positive dose response was observed for abdominal vascular enhancement, with the highest contrast-to-noise ratio observed at 4.0 mg Fe/kg bw at 1.5 T and at 2.5-4 mg Fe/kg bw at 0.5 T.At 1.5 T higher R2*values were calculated for the aorta than for the IVC.</p>
760

Postpartum Ultrasound / Postpartum Ultraljud

Mulic-Lutvica, Ajlana January 2007 (has links)
<p>This study was undertaken to investigate the involutional changes of the uterus and uterine cavity by ultrasound (US), gray-scale and Doppler, after normal delivery, and to compare with the corresponding findings from women with puerperal complications, particularly retained placental tissue (RPT). The overall design was exploratory and prospective, with the use of descriptive statistics for analysis. </p><p>Forty-two women with uncomplicated vaginal term delivery were examined on post-partum days 1, 3, 7, 14, 28 and 56. The AP diameters of the uterus and uterine cavity and morphological findings were recorded. The maximum AP diameters of the uterus and uterine cavity diminished from 92.0 mm on day 1 to 38.9 mm at day 56 and from 15.8 mm at day 1 to 4.0 mm at day 56, respectively. The uterus was most often empty in the early and late puerperium while a mixed echo pattern over the whole cavity was found during mid puerperium (I).</p><p>Seventy-nine women with secondary post partum hemorrhage (SPH) were examined on the day they presented with clinical symptoms. US revealed an echogenic mass in the uterine cavity in 17 of 18 patients treated surgically and histology confirmed placental tissue in 14 of these. Sixty-one patients with either an empty cavity or mixed echo pattern had an uneventful puerperal course after conservative treatment (II).</p><p>AP diameters and morphological findings for 55 women with endometritis, 28 after caesarean section and 20 after manual evacuation of the placenta overlapped extensively with normal references (III).</p><p>The physiological vascular involution studied in 45 women after normal delivery showed that PI and RI indices did not change significantly until day 28 postpartum. The presence of at least one uterine artery notch was found in 13.3% of the women at day 1 and in 90.6% at day 56 postpartum (IV).</p><p>PI and RI values were measured and compared with reference values in 20 women with clinical suspicion of RPT who were to undergo surgical evacuation. Mean resistance indices were below the 10th percentile for eight of these 20 women, but overlapping was considerable. Doppler US has limited value as a diagnostic tool for RPT. The absence of a hyper-vascular area in the myometrium does not exclude RPT but an echogenic mass in the cavity is a sign of RPT (V).</p>

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