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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.
1

An adaptive control grid interpolation technique for the three-dimensional reconstruction of MRI data

Frakes, David Harold 08 1900 (has links)
No description available.
2

The importance of realistic geometry in the study of the total cavopulmonary connection

Ryu, Keesuk 12 1900 (has links)
No description available.
3

Hemodynamic wall shear stress in models of atherosclerotic plaques using phase contrast magnetic resonance velocimetry and computational fluid dynamics

Karolyi, Daniel Roberts 05 1900 (has links)
No description available.
4

The extent of discharge planning by nurses for patients who have undergone valvular surgery

Verwey, Oriana January 2006 (has links)
Valvular disorders can be corrected by means of surgery, after which very comprehensive discharge planning should be implemented to prevent the occurrence of post-operative complications. Advances in medical technology and intellect instigate earlier discharge for patients after they have undergone valvular surgery. The aim of this research study is to establish the extent of discharge planning by nurses for patients who have undergone valvular surgery, so that practice guidelines in the form of an in-service educational framework can be compiled for nurses in the management of these patients post-operatively. Patients, many of whom are from rural areas, are discharged without an adequate referral system. There are, currently, no set guidelines or referral persons to direct these patients during their rehabilitation period. Based on the researcher’s personal observations, it is evident that many patients suffer from bacterial endocarditis or clotted valves due to poor post-surgery management. However, both of these conditions could be avoided if proper health education was given to these patients. The study will take the form of a quantitative, exploratory, descriptive and contextual survey. Data will be collected by means of a structured questionnaire that will be completed by the nurses working in the cardiac general ward and the cardiac clinic. Findings of the research study will be used to assist the researcher in developing an in-service educational framework for staff that are both nursing and preparing post valvular surgery patients for discharge. The goal is to prevent complications such as clot formation and endocarditis and to enable patients to deal effectively with their rehabilitation period.
5

Time-course changes in the echocardiographic parameters and NT-proBNP levels in patients with severe mitral regurgitation undergoing valve replacement.

Prakaschandra, D. R. January 2007 (has links)
Conventional echocardiographic parameters are currently used in determining the timing for surgery in patients with mitral regurgitation. Since brain natriuretic peptide (BNP) rises in response to ventricular muscle stretch, and is to detect early heart failure, we hypothesized that BNP would be activated in patients with regurgitant valvular heart disease and concomitant left ventricular dilatation. Aim/Objectives: We therefore studied the pattern of changes in NT-pro BNP in patients with chronic severe rheumatic mitral regurgitation who were undergoing mitral valve replacement and compared this with the newer modality of tissue Doppler imaging (TDI). Setting: Patients submitted to surgery were prospectively evaluated over 8 months at Inkosi Albert Luthuli Central Hospital, Department of Cardiology. Controls were obtained from the outpatients' follow-up clinic. Methods: Simultaneous quantification of the severity of mitral regurgitation (MR), left ventricular (LV) end systolic volume (ESV), left atrial (LA) volume and Doppler filling ratios (mitral (E)/annulus (Ea)) were performed at baseline in all patients and was repeated at 1-week and at the six-week follow-up visit in surgical patients. Results: Both groups were similar for age and gender and echo-Doppler parameters in all patients preoperatively except LA size (p< 0.01) and volume (p<0.004) which were more elevated in the surgical group. Mean NT-pro BNP levels were markedly elevated preoperatively (262 pmolll) in all surgical cases compared to controls (57 pmol/l; p=0.0001). NT-pro BNP levels increased further at one week post surgery (395 pmol/l) and subsided at the six week follow-up visit (94 pmol/I). These changes were accompanied by significant reduction in LA (p= 0.003) and LV chamber dimensions (EDD = 0.004) with an increase in the ejection fraction from 42% at one week to 52 % at six weeks. Four patients had abnormally elevated NT-pro BNP levels (>53pmol/l) at the 6-week follow-up visit. A ROC curve was constructed for all variables to separate surgical cases from controls. The area under the curve was highest for NT-pro BNP (sensitivity= 96%, specificity 45 %). Conclusion: 1. There was a significant difference in the left atrial chamber size and volume, as well as Em/Ea (TDI) and NT-proBNP levels preoperatively between the two groups. The lack of a significant difference in the LV parameters between surgical and control groups suggest an almost total reliance on symptoms in deciding the timing of surgery which was reflected by markedly elevated NT-pro BNP in all surgical patients. 2. Postoperatively, there was a significant reduction in LA and LV dimensions. 3. The high false positivity rate for NT-pro BNP suggests that the test is most likely reflecting early LV decompensation in the less symptomatic control patients who rightly need surgery. 4. Tissue Doppler indices had similar sensitivity but low specificity compared to NT-proBNP. 5. Serial estimations of NT-pro BNP may prove useful in selecting patients for surgery. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, 2007.
6

Investigation of acute systemic inflammatory response and myocardial injury after cardiac surgery in patients infected with human immunodeficiency virus

Gojo, Mawande Khayalethu Edson January 2016 (has links)
Submitted in fulfillment of the requirements for the degree of Masters of Health Sciences in Clinical Technology, Durban University of Technology, Durban, South Africa, 2016. / Introduction: The immediate post-cardiopulmonary bypass (CPB) immune responses and organ injuries in immune- compromised patients remain poorly documented. We conducted a prospective clinical study to determine whether or not human immunodeficiency virus (HIV) seropositive patients generate higher acute systemic inflammatory response and suffer greater myocardial injury, compared to HIV seronegative patients. Methodology: Sixty-one consecutive patients i.e. Thirty HIV seropositive patients and Thirty-one seronegative, undergoing elective cardiac valve(s) replacement were enrolled, over a period of nine months from a single center hospital, after informed consent was acquired. The C-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) were used as biomarkers of acute inflammatory response, and cardiac troponin I (cTnI) as a biomarker for measuring postoperative myocardial injury. Single tests were measured preoperatively and postoperatively, in both groups, and these were compared and correlated to perioperative events and CPB parameters. Results: The mean age group was similar between the HIV seropositive and negative group (37.8 and 37.1 years, respectively). Preoperatively both groups had relatively equal CRP levels (p=0.388), ESR levels (p=0.817) and cTnI (p=0.489). The CPB events and durations were significantly different between the two groups, CPB duration (p=0.021). Other CPB events include, clamp aortic duration (p=0.026), CPB blood transfusion (p=0.013), CPB total urine output (p=0.035) and CPB peak lactate (p=0.040). Postoperatively we observed significant increased biomarkers level in both groups, with no significant difference between the groups: mean CRP (p=0.115), mean ESR (p=0.214) and cTnI (p=0.363). We observed a significant negative correlation between the mean change in CRP levels and mechanical ventilation (r=- 0.548, p=0.002) in the seropositive group, but not in the uninfected group (r=0.025, p=0.893). The correlation between the difference in CRP and ICU stay was not significant between in both group (r=-0.231, p=0.229 and r=0.25, p=0.975, respectively). A significant positive correlation between postoperative cTnI and the inotropic support duration (r=0.384, p=0.040) was seen in the seropositive groups, but not in the negative group (r=0.092, p=0.622). Furthermore we observed a significant drop in CD4 cells postoperatively (p=<0.001) in the HIV seropositive group. Antiretroviral treatment appeared to influence the degree of change in CD4 cells postoperatively. Conclusion: We conclude that HIV positive patients’ postoperative reactions to cardiac surgery supported by CPB are similar to those of HIV seronegetive patients. We further report non-paralleling correlations between the biomarkers and perioperative events; however these do not seem to affect the overall outcomes between the two groups. / M

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