Browsing by Subject "Atrial fibrillation"

Now showing 1 - 11 of 11
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    Atrial Fibrillation: Prevention of Strokes
    (2009-09-18) Anderson, Sarah
    Atrial fibrillation is the most common arrhythmia seen in the clinical setting. This so called, irregularly irregular rhythm is associated with thrombosis, or clot formation, in the heart. These clots have the potential to break free and travel to different places in the body, including the brain. Clots traveling to the brain prevent adequate circulation, resulting in a stroke. This pamphlet describes atrial fibrillation, why it has the increased potential to form thromboses, which patients are at increased risks of strokes, and the treatment options including antithrombotic therapies.
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    Atrial fibrillation: relation to the metabolic syndrome, smoking, and development of a clinical risk score.
    (2009-11) Chamberlain, Alanna Marie
    This document provides information on the pathophysiology and epidemiology of atrial fibrillation, along with details on three manuscripts that together form the basis of a doctoral thesis. Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice and poses a great economic burden on the healthcare system. Some well known cardiovascular risk factors, such as smoking and the metabolic syndrome, have not been widely studied in the context of AF. In addition, the majority of studies on AF have used primarily white cohorts from North America and Europe. This dissertation reports the associations of the metabolic syndrome and smoking with incident AF, and provides a 10-year risk prediction score for AF using the Atherosclerosis Risk in Communities (ARIC) study. The ARIC study is a bi-racial cohort of almost 16,000 participants followed since the baseline examination in 1987-1989. The first manuscript describes the association of the metabolic syndrome and the individual components of the metabolic syndrome with risk of incident AF over a mean follow-up of 15.4 years. A 67% increased risk of incident AF was reported for individuals with compared to those without the metabolic syndrome at baseline. Most of the metabolic syndrome components were associated with an increased AF risk, and of the individual components, elevated blood pressure appeared to contribute most to AF risk. In addition, a monotonically increasing risk of AF with increasing number of metabolic syndrome components was observed. In the second manuscript, the associations of smoking status and amount with incident AF in ARIC were examined, and a systematic literature review on prospective cohort studies investigating the effects of smoking on AF incidence was conducted. Current and former smokers exhibited a 98% and 30% increased risk of developing AF compared to never smokers. The risk of incident AF increased with increasing cigarette-years of smoking, and appeared to be somewhat greater among current smokers than former smokers with similar cigarette-years of smoking. However, no consistent association was apparent in previously published studies on smoking and incident AF. A 10-year risk score for AF was developed using risk factors commonly measured in clinical practice for the third manuscript. The risk score had good discrimination and better predicted who would develop AF than the Framingham AF risk score applied to the ARIC cohort. In addition, the Framingham and ARIC coronary heart disease risk scores did not predict the 10-year risk of AF well, highlighting the importance of a separate risk score to predict AF.
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    Atrial fibrillation: surveillane, concordance, and healthcare utilization
    (2013-10) Smith, Lindsay Garnier
    Background information on the epidemiology of atrial fibrillation (AF), including descriptive data and risk factors, pathophysiology, clinical aspects and outcomes, as well as three original manuscripts that together form the basis of this doctoral dissertation, are presented. The objectives of this dissertation were to assess temporal trends in the occurrence and prognosis of AF among acute myocardial infarction (MI) patients, to determine the usefulness of administrative data to identify incident AF, and to describe the impact of AF on healthcare utilization. AF in the setting of MI occurs frequently and is associated with increased mortality. Nonetheless, temporal trends in the occurrence of AF complicating MI and in the prognosis of these patients are not well described. In a population-based sample of 20,049 validated first incident nonfatal hospitalized MIs from the Atherosclerosis Risk in Communities (ARIC) Study, prevalence of AF in MI increased from 11% to 15% (adjusted odds ratio [OR] for prevalent AF: 1.11; 95% confidence interval [CI]: 1.04 - 1.19 per five-year increment) from 1987 through 2009. In patients with MI, AF was associated with increased 1-year mortality (adjusted OR 1.47, 95% CI 1.07-2.01) compared to those without AF. However, there was no evidence that the impact of AF on MI survival changed over time or differed over time by sex, race or MI classification. In the setting of MI, co-occurrence of AF should be considered a critical clinical event and treatment needs unique to this population should be explored further. Increasingly, epidemiologic studies use administrative data to identify AF. Capture of incident AF is not well documented. ARIC cohort participants without prevalent AF enrolled in fee-for-service Medicare, Parts A and B, for at least 12 continuous months between 1991 and 2009 were included. Of 10,134 eligible participants, 738 developed AF according to both ARIC and Centers for Medicare and Medicaid Services (CMS); an additional 93 and 288 incident cases were identified using only ARIC and CMS data, respectively. Incidence rates per 1,000 person-years were 10.8 (95% CI: 10.1-11.6) and 13.6 (95% CI: 12.8-14.4) in ARIC and CMS, respectively; agreement was 96%; the kappa statistic was 0.77 (95% CI: 0.75-0.80). Additional CMS events did not alter observed associations between risk factors and AF. Drawbacks of CMS are its inapplicability to those <65 years and inability to capture AF for those with Medicare Advantage. AF is associated with increased risk of hospitalizations. However, little is known about the impact of AF on non-inpatient healthcare utilization or about sex or race differences in AF-related utilization. ARIC cohort participants with incident AF (n=944) enrolled in fee-for-service Medicare, Parts A and B, for at least 12 continuous months between 1991 and 2009 were matched on age, sex, race and center to up to three participants without AF (n=2,761). The average annual days hospitalized were 13.1 (95% CI: 11.5-15.0) and 2.8 (95% CI: 2.5-3.1) for those with and without AF, respectively; the annual numbers of outpatient claims were 53.2 (95% CI: 50.4-56.1) and 23.0 (95% CI: 22.2-23.8) for those with and without AF, respectively. Most utilization in AF patients was attributable to non-AF conditions, particularly other- cardiovascular disease-related reasons. There was suggestive evidence that sex modified the association between AF and inpatient utilization, with AF related to greater utilization in women than men. The association between AF and healthcare utilization was similar in whites and blacks. In addition to rate or rhythm treatment, management of AF also should focus on the accompanying cardiovascular comorbidities. Overall, the results from this dissertation indicate that co-occurrence of AF in MI is a critical clinical event, that administrative data can be useful in AF epidemiologic research, and AF patients have substantial healthcare utilization, especially for other-cardiovascular disease-related reasons.
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    Atrial Fibrillation: What is it and what are my options?
    (2008-09-02) Mooney, Joshua
    This brochure is a patient’s guide to the risk factors, symptoms, diagnosis and management of atrial fibrillation. There is an explanation of the treatment options available with a specific focus on the available medications to prevent stroke.
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    Blood Thinners: Which one is right for me?
    (2012-07-23) Prudom, Jason S.
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    Preventing Stroke in Patients with Atrial Fibrillation
    (2012-07-24) Petersen, Elizabeth
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    The Role of Protein Change (Cellular Protein Loss and Denaturation) in Determining Outcomes of Heating, Cryotherapy and Irreversible Electroporation
    (2018-04) Liu, Feng
    Atrial fibrillation currently affects millions of people in the US alone. Focal therapy is an increasingly attractive treatment for atrial fibrillation that avoids the debilitating effects of drugs for disease control. Perhaps the most widely used focal therapy for atrial fibrillation (AF) is heat-based radiofrequency (heating), although cryotherapy (cryo) is rapidly replacing it due to a reduction in side effects and positive clinical outcomes. A third focal therapy, irreversible electroporation (IRE), is also being considered in some settings. This study was designed to help guide treatment thresholds and compare mechanism of action across heating, cryo, and IRE. Testing was undertaken on HL-1 cells, a well-established cardiomyocyte cell line, to assess injury thresholds for each treatment method. Cell viability, as assessed by Hoechst and PI staining, was found to be minimal after exposure to temperatures ≤-40 °C (cryo), ≥60 °C (heating), and when field strengths ≥1500 V/cm (IRE) were used. Viability was then correlated to protein denaturation fraction (PDF) as assessed by Fourier Transform Infrared (FTIR) spectroscopy, and protein loss fraction (PLF) as assessed by Bicinchoninic Acid (BCA) assay after the three treatments. These protein changes were assessed both in the supernatant and the pellet of cell suspensions post treatment. We found that dramatic viability loss (≥50%) correlated strongly with ≥12% protein change (PLF, PDF or a combination of the two) in every focal treatment. These studies help in defining both cellular thresholds and protein-based mechanisms of action that can be used to improve focal therapy application for atrial fibrillation.
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    Should I Monitor My Coumadin at Home?
    (2012-07-24) Knapper, Joe
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    Understanding Atrial Fibrillation
    (2012-09-24) Ellingson, Sonja