Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 44-47).

Thesis (Ph. D.)--Brigham Young University. Dept. of Psychology, 2008. / Includes bibliographical references (p. 31-36).

Thesis (M.S.)--University of Wisconsin--La Crosse, 2002. / Includes bibliographical references.

Thesis (M.S.)--Iowa State University, 2005. / Includes bibliographical references (leaves 31-34).

Thesis (M.S.)--Iowa State University, 2005. / Includes bibliographical references (leaves 31-34). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Made available in DSpace on 2014-06-11T19:28:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-10Bitstream added on 2014-06-13T20:37:41Z : No. of bitstreams: 1 cunha_mgs_me_guara.pdf: 2546988 bytes, checksum: 7f90dfedf806a463275bbea800769557 (MD5) / O presente trabalho consiste no estudo do comportamento do fluxo sangüíneo na artéria braquial, através de sinais captados por um microfone acoplado no estetoscópio e utilizado para transformar o sinal acústico (sonoro) em elétrico, e enviá-lo para o computador. O estudo foi realizado oferecendo-se diferentes pressões no esfigmomanômetro, o qual foi adaptado com dois manômetros. Um dos manômetros, graduado em mmHg, não foi modificado, possui o selo do INMETRO e atuou como referência, ao outro foi inserido um extensômetro, que transformou o sinal de pressão em sinal elétrico, utilizando uma ponte amplificada, enviando-o para uma placa de aquisição de dados no computador. Foi traçada uma curva de calibração do sinal elétrico (em mV) com relação ao manômetro graduado em mmHg. Foi proposto um protocolo para aquisição destes sinais a serem analisados, baseado em protocolos de aferição de pressão arterial. O comportamento do fluxo sangüíneo foi comparado às diferentes pressões exercidas pelo esfigmomanômetro. Ao analisar estes dados, foram propostos limites de normalidades da intensidade do sinal do fluxo sangüíneo em diferentes freqüências nas cinco fases da escala de Koroktov. O trabalho mostrou também os limites de normalidade da pressão arterial, utilizando-se o sinal adquirido pela extensometria. Finalmente, foi oferecido mais um auxílio no diagnóstico de patologias do sistema cardiovascular. / The present work consists to study the features of blood flow in to the brachial artery through signals detected by a microphone coupled together a stethoscope. This apparatus changes the acoustics in eletric signal and, then, sends to the computer. This study was implemented exhibiting different pressures in the sphygnomanometer, where two manometers, graded in mmHg, were coulpled. One that has the INMETRO certificate of gauging instruments was not modificate and, then, it was used as the standard. In the other, an extensometer was coupled together, which through an amplifier bridge, pressure signals are transformed in electric signals and sent to a data adapter unit connected to the computer. A gauging curve for the eletric signals versus pressure signals was ploted. It was proposed a protocol to adquire these data signals, based on the protocol of brachial pressure measurement. The features of blood flow were compared at different sphygnomanometer pressures. In the analysis process of the data, normality boundaries of intensity were proposed to the blood flow signal at different frequencies in the five phases of the Koroktov scale. The work also showed the normality boundaries of brachial pressure using the data signals adquired by the extensometry process. Finally, it was provided an one more aid in to diagnose pathologies in the cardiovascular system.

Background: the incidence of high blood pressure in South Africa has increased over the past few decades (Chopra et al., 2009; Seedat, 2012). Public health scientists have warned that this trend might be correlated to a multitude of unhealthy behaviors at the individual level, including heavy alcohol consumption (Chopra et al., 2009; Hillbom et al., 2011; Seedat, 2012; Strogatz et al., 1991). Previous studies have established a synergistic effect between alcohol consumption and high blood pressure leading to an increased risk of cardiovascular and renal disease within countries of the global north (Abe et al., 1994; Keil et al., 1993; Steyn et al., 1997). Not only is this trend under studied in South Africa, the severity of alcohol’s impact on blood pressure remains to be discerned in the country. Objectives: shedding light on the epidemiological and social factors impacting the association between alcohol consumption and blood pressure. Based on previous observations, it is hypothesized that certain epidemiological factors will be strongly associated with high blood pressure in the presence of alcohol consumption. Findings from this research would inform healthcare professionals on the diagnosis of high blood pressure cases in the South African population as this research aims to identify the factors associated with high blood pressure, thus, alleviating the problem of underdiagnosed cases that have been found to incur heavy costs on the healthcare system (Chopra et al., 2009; Seedat, 2012). Methods: in the present study, we have investigated social and epidemiological factors, as informed by previous research, which are associated with blood pressure in the presence of alcohol consumption within a South African context by using data collected from the South African Demographic and Health Survey (SADHS). Conclusion: Our findings indicate a correlation between ethnicity and blood pressure, as well as having a heart attack and high blood pressure measurements.

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, for the degree of Doctor of Philosophy. Johannesburg, South Africa September 2017. / Although brachial blood pressure (BP) is a well-recognized risk factor for predicting cardiovascular events, aspects of aortic BP may enhance risk prediction. Pulse pressure (PP) is amplified from the aorta to peripheral arteries and variations in differences between brachial and aortic PP (PP amplification) are determined by factors that influence either the aortic forward (Pf) or backward (Pb)(reflected) pressure waves. Although aortic Pb may be more important than Pf in mediating cardiovascular risk, the best approach to assessing backward wave function (augmentation pressures [Pa] and index [AIx] or wave separation analysis); the relative impact of aortic Pb versus Pf on cardiovascular damage; and whether the ability of aortic-to-brachial PP amplification (PPamp) to add to risk prediction reflects backward or forward wave effects, is uncertain. In the present thesis I therefore first assessed in 808 community participants whether gender influences relations between Pa or AIx and left ventricular mass (LVM), a well-accepted end-organ measure. Aortic haemodynamics were determined using radial applanation tonometry and SphygmoCor software and LVM from echocardiography. In men, both AIx derived from Pa/central aortic PP (Pa/PPc) (p<0.01) and AIx derived from the second peak/first peak (P2/P1) of the aortic pulse wave (p<0.0005) were associated with LVM. In contrast, in women neither AIx derived from Pa/PPc (p=0.08) nor AIx derived from P2/P1 (p=0.17) were associated with LVM. Both the strength of the correlations (p<0.001 and p<0.0005) and the slope of the AIx-LVM relationships (p=0.001 and p<0.0005) were greater in men as compared to women. Therefore, in the present study I show that AIx is independently associated with LVMI in men, but not in women. I subsequently evaluated whether in women, measures of aortic systolic pressure augmentation (Pa or AIx) underestimate the effects of reflected waves on cardiovascular risk or whether Pb plays little role in cardiovascular risk prediction. In the same community sample I therefore evaluated sex-specific contributions of reflected (Pb and the reflection index [RI]) versus augmented (Pa and AIx) pressure wave indices to iii variations in PPc (n=1185, 65.0% women), and LVM (n=793, 64.9% women). Aortic Pb and Pf were determined using wave separation analysis. In both women and in men, independent of confounders, RI and Pb contributed more than Pf, whilst Pa and AIx contributed less than incident wave pressure (Pi) to variations in PPc (p<0.0001 for comparison of partial r values). In both men and in women Pb contributed more than Pf (p<0.05) to variations in LVM. Although in men Pa (partial r=0.33, p<0.0001) contributed to a similar extent as Pi ((partial r=0.34, p<0.0001) to variations in LVMI, in women Pa (partial r=0.05, p=0.36) failed to contribute to LVM, whilst Pi was significantly associated with LVM (partial r=0.30, p<0.0001). Similar results were obtained with AIx as opposed to Pa in the regression models. Therefore, in both women and in men, Pb is more closely associated with PPc and LVM than Pf, but indices of aortic pressure augmentation markedly underestimate these effects, particularly in women. As the relative impact of aortic Pb as compared to Pf on cardiovascular damage independent of brachial BP is uncertain, in 1174 participants from a community sample I subsequently assessed the relative impact of Pb and Pf on variations in LVM (n=786), aortic pulse wave velocity (PWV)(n=1019), carotid intima-media thickness (IMT)(n=578), transmitral early-to-late LV diastolic velocity (E/A)(n=779) and estimated glomerular filtration rate (eGFR)(n=1174). Independent of mean arterial pressure and confounders, PPc and both Pb and Pf were associated with end-organ measures or damage (p<0.05 to <0.0001). With adjustments for brachial PP and confounders, Pb remained directly associated with LVM (partial r=0.10, p<0.01), PWV (partial r=0.28, p<0.0001), and IMT (partial r=0.28, p<0.0001), and inversely associated with E/A (partial r=-0.31, p<0.0001) and eGFR (partial r=-0.14, p<0.0001). Similar relations were noted with the presence of end-organ damage (p<0.05 to <0.0001). In contrast, with adjustments for brachial PP and confounders, Pf no longer retained direct relations with LVM, PWV, and IMT or inverse relations with E/A and eGFR. Adjustments for Pb, but not Pf diminished brachial PP-independent relationships between PPc and end-organ measures. Thus, although both Pf and Pb contribute to end-organ measures and damage, independent of brachial iv BP, the impact of aortic BP is accounted for largely by Pb. PPamp is independently associated with cardiovascular outcomes. However, the aortic functional change most likely to account for this effect is uncertain. In 706 community participants I subsequently aimed to identify the aortic functional change that accounts for relations between PPamp and LVM. In multivariate models with the inclusion of brachial PP, 1/PPamp (partial r=0.12, p<0.005), Pb (partial r=0,09, p<0.05), and aortic PWV (partial r=0.09, p<0.05) were independently associated with LVMI. Similarly, in multivariate models with the inclusion of brachial PP, 1/PPamp (p<0.005), Pb (p<0.01), and aortic PWV (p<0.01) were independently associated with LV hypertrophy (LVH). With adjustments for Pb, the brachial PP-independent relationships between 1/PPamp and LVMI or LVH were abolished (p>0.08 for both). However, adjustments for PWV failed to modify brachial PP-independent relations between 1/PPamp and LVMI or LVH. Hence, independent relations between PPamp and LVM or LVH are largely accounted for by Pb. In conclusion, in the present thesis I show that the use of augmented pressures underestimates the impact of reflected pressure wave effects on end-organs, particularly in women; that brachial BP-independent relations between aortic BP and end organs is determined largely by Pb and that relations between PPamp and end organ measures is largely accounted for by Pb. These findings add to our understanding of the adverse effects of aortic functional changes on the cardiovascular system and suggest cost-effective approaches to add to risk prediction. / LG2018

Exposure to adverse childhood experiences (ACEs) has lasting repercussions throughout an individual’s lifetime. An adult with a history of childhood trauma is at increased risk for excessive stress reactivity, which exacerbates the development of chronic disease. It is important to investigate how this information can be used for adult trauma survivors. This study assessed the psychophysiological impacts of providing “ACE insight”. Participants completed questionnaires and were given false feedback that their childhood experiences put them at increased risk for excessive stress reactivity and the development of disease. Following ACE insight, participants underwent a speech stressor task during which cardiovascular reactivity was monitored and psychological reactions were assessed. Results indicated that participants with more adverse childhoods reported feeling more worried and less happy about feedback. Further, ACE insight caused a significant increase in cardiac output for participants with a history of childhood trauma. Implications and future directions are discussed.

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