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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.
311

The renal medullary circulation and blood pressure control

Correia, Anabela, G., 1975- January 2001 (has links)
Abstract not available
312

Statistical analysis of central aortic blood pressure parameters derived from the peripheral pulse

Camacho, Fernando, Graduate School of Biomedical Engineering, Faculty of Engineering, UNSW January 2006 (has links)
With the rise in prevalence of cardiovascular (CV) disease, risk stratification is becoming increasingly important. Accurate characterization of the CV system is required, for which central aortic blood pressure (BP) parameters form an integral part. However, invasive measurement of central aortic BP parameters (aP) is difficult. Therefore, non-invasive methods to estimate aP from the radial pressure pulse (rPulse) have been proposed. To analyze accuracy of estimated aP (aPhat) and applicability in risk stratification and diagnosis, this study presents: (1) a novel representation of the rPulse with minimal loss of information, (2) a framework for strict definition and statistical analysis of aPhat, and (3) a dynamic analysis of effects of mean BP (MP) and heart rate (HR) in the rPulse shape. Methods: (1) 2671 rPulse s measured by applanation tonometry were represented using the first eight principal components (PC) scores after standard PC transformation. rPulse shapes were compared in three subpopulations. (2) The concept of &quotestimation option&quot (EO) for aP estimation was presented. A framework for strict definition of aPhat and the comparison of EOs was proposed, and 7 different EOs compared. (3) A sequence of rPulse s was analyzed during soft exhalation maneuver (SEM) %, a mild Valsalva type maneuver, in eight healthy subjects. Radial BP and respiration pressure were continuously measured. The effects of MP and HR in the rPulse parameters were analyzed by standard linear regression for each subject. Results: (1) PC representation of the rPulse improves accuracy of the estimation of aPhat compared with the simple use of rPulse parameters. Subpopulations have distinctive rPulse shapes. (2) No single EO was better for the estimation of all aPhat. Inclusion of MP improves estimation accuracy. Despite further improvement when rPulse is included, the general transfer function EO is a biased estimator. (3) The dynamic analysis of the rPulse provides information of the effects of MP and HR in the rPulse not available in static analysis. The effects were specific for each individual and different from the results obtained from a general population. Conclusions: For accurate CV risk stratification, future studies should include a dynamic measurement of calibrated radial pressure pulse during SEM maneuver. Risk analysis and diagnosis should be based on representations of the rPulse with minimum loss of information. aPhat should be used for better understanding of the underlying physiological principles.
313

Association Between Obesity and Therapeutic Goal Attianment in Patients with Concomitant Hypertension and Dyslipidemia

Chopra, Ishveen 17 July 2014 (has links)
Objective: A retrospective study was conducted to examine the variations in therapeutic {blood pressure (BP) and lipid} goal attainment and medication utilization pattern in patients with concomitant hypertension and dyslipidemia, specifically comparing obese versus non-obese patients. Methods: GE Centricity EMR database containing data from 2004-2011 was utilized. 9,086 patients diagnosed with concomitant hypertension and dyslipidemia were evaluated. Goal attainment and treatment pattern for BP and lipid levels was assessed based on JNC 7 and NCEP ATP III guidelines, respectively. Results: Substantial proportion of patients with concomitant hypertension and dyslipidemia failed to attain BP and lipid goals. Further, in patients with concomitant hypertension and dyslipidemia, obesity appears to be an independent risk factor for the failure to attain BP and dual BP/LDL-C. Conclusions: With increasing prevalence of obesity and inadequate therapeutic goal attainment in these populations, healthcare professionals should use appropriate treatment strategies for improving the management of cardiovascular risk factors (hypertension, dyslipidemia, and obesity). / Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences / Pharmacy Administration / MS / Thesis
314

The Effects of an Incremental Pedometer Program on Metabolic Syndrome Components in Sedentary Overweight Women

Musto, Anthony 25 April 2008 (has links)
Objective: Pedometer programs are effective in increasing physical activity in sedentary individuals, a population that is at an increased for developing metabolic syndrome and each of its individual components. The aim of this study was to observe the effects of incremental increases in pedometer assessed physical activity on MetS components in sedentary overweight women. Design: This study was a longitudinal, quasi-experimental design. Participants were recruited from a 12-week work-site pedometer program and grouped after the intervention based on their self-paced increases in pedometer assessed physical activity with (a) active participants that increased their daily activity by mean volume >3000 steps/day or (b) participants who remained sedentary. Subjects: A multi-ethnic heterogeneous sample of seventy-seven sedentary middle-aged women (BMI: 30.15 plus or minus 5.24 kg/m2, age: 46.00 plus or minus 9.93 years). Measurements: Self-reported physical activity, pedometer assessed physical activity (steps/day), body mass index, resting heart rate, waist circumference, blood pressure, triglycerides, HDL-C and fasting glucose at baseline and after the 12-week program. Results: The active group showed significant within-group improvements (P less than or equal to .01) in waist circumference and fasting glucose. Significant between group changes were observed in resting heart rate (P less than or equal to .01), weight (P less than or equal to .01), BMI (P less than or equal to .01), and systolic blood pressure (P less than or equal to .001); however, the changes observed in systolic blood pressure were not independent of weight loss. Conclusions: Our study showed that incremental increases in steps/day over 12 weeks is effective in inducing mild, but favorable changes in some MetS components. This data suggests that this approach to increasing step/day is a viable starting point for sedentary individuals that may find it difficult to initially accumulate 10,000 steps/day.
315

Effects of nicotine and streptozotocin on the cardiovascular system

Peterson-Wakeman, Robert S. 03 February 2005
Our study investigated the potential for a combination of diabetes and nicotine treatment to affect blood pressure in the rat. We used streptozotocin injection and oral nicotine feeding as models of type-1 diabetes and smoking respectively. Blood pressure was assessed using the indirect tail-cuff technique. In an attempt to further characterize our experimental model, we also observed body weight, plasma glucose and the contractility of aortic segments in various treatment groups. Our data was expressed as mean ± SEM, and significance was regarded as P < 0.05. We found that a combination of streptozotocin and nicotine treatment resulted in a significant elevation of systolic blood pressure compared with either treatment alone, or control. Furthermore, assessment of aortic contractility showed alteration of reactivity to both phenylephrine and sodium nitroprusside as a result of the combination treatment. We also observed a trend for our combination treatment to exacerbate the elevation of plasma glucose level seen in streptozotocin induced diabetic rat models. This study serves as an experimental basis to underline the importance of cessation of tobacco use for individuals with diabetes mellitus.
316

The Relationship between Acute and Chronic Aerobic Exercise Response in Pre-hypertensive Individuals

Liu, Sam 10 January 2011 (has links)
Aerobic exercise is recommended as a lifestyle intervention to reduce blood pressure (BP) in individuals with elevated BP (SBP/DBP >120/80 mmHg). However, the BP response is highly variable after both acute (SBP/DBP: –27 to 9/-8 to 7mmHg) and chronic aerobic exercise (-20 to 9/ -11 to 11.3mmHg). We attempt to identify those who are resistant or responsive to training based on their responses to acute (one-bout) exercise. 17 prehypertensive (120 to 139/80 to 89mmHg) males and females (45-60yrs) underwent acute exercise assessments before and after an 8-week walking/jogging program. The magnitude of change in BP after acute exercise significantly correlated (r=.89, p < .01) with the magnitude of change in resting BP after the training. The antihypertensive mechanisms (total peripheral resistance, baroreflex sensitivity) for acute exercise were not correlated to those for chronic exercise. Central cardiovascular controls may link BP reductions after both acute and chronic exercise.
317

Effects of Moderate-intensity Aerobic Cycling and Swim Exercise on Post-exertional Blood Pressure in Healthy, Young Men and Women

Lakin, Robert 26 July 2012 (has links)
Aerobic exercise such as cycling is known to elicit a post-exercise hypotensive (PEH) response. However, it is not known if swim exercise produces a similar effect in normotensive individuals. We tested the hypothesis that an acute bout of swimming would elicit a PEH response that is less compared to an equivalent bout of cycling. 10 trained and 11 untrained normotensive (SBP/DBP < 120/80 mmHg) individuals (23±1 years) underwent 30 min intensity-matched cycling and swimming sessions to assess changes in BP and cardiovascular responses. While PEH was similar between modalities within groups, the magnitude and temporality of change in BP following swimming was significantly different (p < 0.01) between groups, with untrained participants showing a significant PEH response. Attenuation of PEH in trained individuals was reflective of a significant increase in sympathetic outflow and slower vagal reactivation, suggesting training in an aquatic environment leads to alterations in post-exercise BP regulatory mechanisms.
318

The Relationship between Acute and Chronic Aerobic Exercise Response in Pre-hypertensive Individuals

Liu, Sam 10 January 2011 (has links)
Aerobic exercise is recommended as a lifestyle intervention to reduce blood pressure (BP) in individuals with elevated BP (SBP/DBP >120/80 mmHg). However, the BP response is highly variable after both acute (SBP/DBP: –27 to 9/-8 to 7mmHg) and chronic aerobic exercise (-20 to 9/ -11 to 11.3mmHg). We attempt to identify those who are resistant or responsive to training based on their responses to acute (one-bout) exercise. 17 prehypertensive (120 to 139/80 to 89mmHg) males and females (45-60yrs) underwent acute exercise assessments before and after an 8-week walking/jogging program. The magnitude of change in BP after acute exercise significantly correlated (r=.89, p < .01) with the magnitude of change in resting BP after the training. The antihypertensive mechanisms (total peripheral resistance, baroreflex sensitivity) for acute exercise were not correlated to those for chronic exercise. Central cardiovascular controls may link BP reductions after both acute and chronic exercise.
319

Effects of Moderate-intensity Aerobic Cycling and Swim Exercise on Post-exertional Blood Pressure in Healthy, Young Men and Women

Lakin, Robert 26 July 2012 (has links)
Aerobic exercise such as cycling is known to elicit a post-exercise hypotensive (PEH) response. However, it is not known if swim exercise produces a similar effect in normotensive individuals. We tested the hypothesis that an acute bout of swimming would elicit a PEH response that is less compared to an equivalent bout of cycling. 10 trained and 11 untrained normotensive (SBP/DBP < 120/80 mmHg) individuals (23±1 years) underwent 30 min intensity-matched cycling and swimming sessions to assess changes in BP and cardiovascular responses. While PEH was similar between modalities within groups, the magnitude and temporality of change in BP following swimming was significantly different (p < 0.01) between groups, with untrained participants showing a significant PEH response. Attenuation of PEH in trained individuals was reflective of a significant increase in sympathetic outflow and slower vagal reactivation, suggesting training in an aquatic environment leads to alterations in post-exercise BP regulatory mechanisms.
320

Cuff-free blood pressure estimation using signal processing techniques

Zhang, Qiao 13 September 2010
Since blood pressure is a significant parameter to examine people's physical attributes and it is useful to indicate cardiovascular diseases, the measurement/estimation of blood pressure has gained increasing attention. The continuous, cuff-less and non-invasive blood pressure estimation is required for the daily health monitoring. In recent years, studies have been focusing on the ways of blood pressure estimation based on other physiological parameters. It is widely accepted that the pulse transit time (PTT) is related to arterial stiffness, and can be used to estimate blood pressure.<p> A promising signal processing technology, Hilbert-Huang Transform (HHT), is introduced to analyze both ECG and PPG data, which are applied to calculate PTT. The relationship between blood pressure and PTT is illustrated, and the problems of calibration and re-calibration are also discussed. The proposed algorithm is tested based on the continuous data from MIMIC database. To verify the algorithm, the HHT algorithm is compared with other used processing technique (wavelet transform). The accuracy is calculated to validate the method. Furthermore, we collect data using our own developed system and test our algorithm.

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