Thesis (D.Sc.)--University of Adelaide, Dept. of Biochemistry, 1979.

Thesis (Ph. D.)--University of Hong Kong, 1993.

Thesis--Wisconsin. / Includes bibliographical references (leaves 75-80).

Thesis (M.A.)--Boston University

A paper submitted to The University of Arizona College of Medicine - Phoenix, History of Medicine course.

No description available.

Note:

Reviews of clinical practice for paediatric pacemaker implantation and follow-up are necessary to provide an evidence-base for future policy and practice in this field. Epicardial pacing data available through Green Lane Hospital, New Zealand's (NZ) primary referral centre for paediatric cardiac surgery and pacemaker implantation, was reviewed with the following aims: Assessment of pacemaker lead performance over time in relation to the type of epicardial lead implanted - steroid-eluting (SE) and non steroid-eluting (NSE). Determination of the survival rate of epicardial leads. Identifying factors predicting or associated with lead failure.A database of pacing and sensing thresholds and lead impedance data at implant, 2, 6 and 18 weeks and 6 monthly intervals thereafter, was compiled and the prevalence and timing of complications in relation to lead type, location and implant route determined. In total 192 leads (155 SE, 37 NSE) were implanted in 96 patients (52 male) aged 3 days to 71 years (y) (median 1.7y), 74 patients were < 17 years of age at implant. Congenital heart defects were present in 82% of patients. Follow-up (f/u) was possible for 180 leads. Mean f/u duration for the 150 SE leads was 3.1y (2 weeks - 8.8y) and for the 30 NSE leads was 4.5y (2 weeks - 27y).SE and NSE pacing thresholds were similar at implant. NSE pacing thresholds peaked at 6 weeks post implant and remained significantly higher than SE leads throughout f/u in surviving leads, although the difference was small at 2 and 4 y. SE and NSE leads had similar ventricular sensing thresholds and lead impedances throughout the study period.Survival at 5 years for all leads was 61% (66% for SE leads and 41% for NSE leads). Primary causes of failure in the leads receiving f/u were exit block and lead fracture. The occurrence of exit block was significantly higher (p<0.0001) in NSE leads (57%) compared to SE leads (5%). Lead fracture occurred in 15% of leads with the highest fracture rate at 2-3 y post implant. Patient age and weight at implant, gender, previous cardiac surgery, lead polarity, indication for pacing and implant route were not predictors of lead failure. NSE leads were 6 times more likely to fail compared to SE leads (p <0.0001).The main study findings were: SE leads maintain lower pacing thresholds and a reduced incidence of exit block compared to NSE leads. It is therefore recommended that SE leads be developed which can penetrate fibrosed, scarred or fatty epicardial surfaces. Where SE lead use is contraindicated, alternative surgical techniques for SE lead placement should be attempted rather than implanting NSE leads. Lead fracture is a significant complication of epicardial pacing in paediatric patients. Using stronger bipolar leads implanted by the subxiphoid route may reduce the risk of fracture. Medium term survival (5 y) of SE epicardial leads is acceptable and therefore the continued use of these leads is recommended, particularly in young patients, allowing their veins to be saved for transvenous leads later in their life.

Reviews of clinical practice for paediatric pacemaker implantation and follow-up are necessary to provide an evidence-base for future policy and practice in this field. Epicardial pacing data available through Green Lane Hospital, New Zealand's (NZ) primary referral centre for paediatric cardiac surgery and pacemaker implantation, was reviewed with the following aims: Assessment of pacemaker lead performance over time in relation to the type of epicardial lead implanted - steroid-eluting (SE) and non steroid-eluting (NSE). Determination of the survival rate of epicardial leads. Identifying factors predicting or associated with lead failure.A database of pacing and sensing thresholds and lead impedance data at implant, 2, 6 and 18 weeks and 6 monthly intervals thereafter, was compiled and the prevalence and timing of complications in relation to lead type, location and implant route determined. In total 192 leads (155 SE, 37 NSE) were implanted in 96 patients (52 male) aged 3 days to 71 years (y) (median 1.7y), 74 patients were < 17 years of age at implant. Congenital heart defects were present in 82% of patients. Follow-up (f/u) was possible for 180 leads. Mean f/u duration for the 150 SE leads was 3.1y (2 weeks - 8.8y) and for the 30 NSE leads was 4.5y (2 weeks - 27y).SE and NSE pacing thresholds were similar at implant. NSE pacing thresholds peaked at 6 weeks post implant and remained significantly higher than SE leads throughout f/u in surviving leads, although the difference was small at 2 and 4 y. SE and NSE leads had similar ventricular sensing thresholds and lead impedances throughout the study period.Survival at 5 years for all leads was 61% (66% for SE leads and 41% for NSE leads). Primary causes of failure in the leads receiving f/u were exit block and lead fracture. The occurrence of exit block was significantly higher (p<0.0001) in NSE leads (57%) compared to SE leads (5%). Lead fracture occurred in 15% of leads with the highest fracture rate at 2-3 y post implant. Patient age and weight at implant, gender, previous cardiac surgery, lead polarity, indication for pacing and implant route were not predictors of lead failure. NSE leads were 6 times more likely to fail compared to SE leads (p <0.0001).The main study findings were: SE leads maintain lower pacing thresholds and a reduced incidence of exit block compared to NSE leads. It is therefore recommended that SE leads be developed which can penetrate fibrosed, scarred or fatty epicardial surfaces. Where SE lead use is contraindicated, alternative surgical techniques for SE lead placement should be attempted rather than implanting NSE leads. Lead fracture is a significant complication of epicardial pacing in paediatric patients. Using stronger bipolar leads implanted by the subxiphoid route may reduce the risk of fracture. Medium term survival (5 y) of SE epicardial leads is acceptable and therefore the continued use of these leads is recommended, particularly in young patients, allowing their veins to be saved for transvenous leads later in their life.

Magister Scientiae (Physiotherapy) - MSc(Physio) / An increase of cardiac surgeries globally has been associated with an increasing number of people with cardiovascular disease in both developed and developing countries. Following cardiac surgery, pulmonary complications are an important cause of morbidity leading to significant prolonged hospitalisation, mortality and overall hospital costs. Physiotherapists have been part of cardiac multidisciplinary team playing a role in prevention and managing respiratory complications post-operatively. Numbers of studies have investigated on the efficacy of physiotherapy interventions in managing patients following cardiac surgery. However, there is no consensus in the literature with regards to intensity, duration of the session and content of therapy in this specialised area of cardio-pulmonary. These variations of physiotherapy intervention have made difficult to find agreement on the necessity of physiotherapy care in the post-operative management of patients following cardiac surgery. To date, however, there have been limited or no studies done on the role of physiotherapy in the Cardiac Unit setting. Thus, the aim of the study was to investigate the role of physiotherapy in the post-operative management of patients following cardiac surgery at Muhimbili National Hospital (MNH), Tanzania. An explanatory sequential mixed method study design was used. A descriptive retrospective study design was chosen for the quantitative phase using a convenient sample of all 105 patients’ records operated from January 2010 to 31st December 2013. With regards to the qualitative phase, 2 Cardiac Surgeons and 10 Physiotherapists working at MNH were conveniently sampled to explore their perceptions on the post-operative role of physiotherapy in the management of patients following cardiac surgery at MNH. Ethical clearance was obtained from the University of the Western Cape and Muhimbili National Hospital to conduct the study. Anonymity and confidentiality was ensured for all participants and their participation was voluntary. They were allowed to withdraw from the study anytime without any negative consequences. Following ethical issues; quantitative data (i.e. profile and process of care of patients) was collected by means of a data extraction sheet while the two separate semi-structured interview guides were used for qualitative data. A total of 105 patients’ records were obtained. Quantitative data was analysed using SPSS 22.0 version. A descriptive statistics was used. The mean age of the study sample was 30.6 (SD=10.5). More than half (54.3%) were females and males 45.7% of the sample. The results show that Rheumatic Heart Disease (RHD) accounted for the majority (74.3%) of cardiac diseases. Double valve repair accounted for 71.4%. A decline in the number of surgeries performed were noted from 2010 (48.6%) to 2013 (10.5%). The mean number of days spent in Intensive Care Unit (ICU) were 6.4 (SD=5.3) and in the ward 12.2 (SD=7.8). A total of 21.4% of the sample developed post-operative complications and 10.5% of the total sample died. A substantial number of patients (77.7%) were referred for physiotherapy treatment post-operatively, with most of these referrals (70.0%) on the first day post-operatively. The majority (37.8%) of the patients received 3 physiotherapy sessions in the ICU with most of these patients (79.3%) being seen once a day in the ICU and (65.8%) in the ward. Physiotherapists prescribed (53.7%) a combination of breathing exercises, active limb mobilisation, incentive spirometry and progressive ambulation in the ICU. A combination of breathing exercises, active limb mobilisations, endurance training and posture correction was frequently (89.5%) prescribed in the ward. Content analysis was used to analyse qualitative data. Cardiac Surgeons were aware of the role of Physiotherapists on the post-operative management of patients following cardiac surgery. They also identified shortcomings on the side of Physiotherapists’ in terms of poor co-operation, inadequate skills and a lack of motivation to work in the Cardiac Unit. On the other hand, Physiotherapists revealed that there was communication breakdown between them and Cardiac Surgeons. They added that they were not motivated to work in the Cardiac Unit due to their inadequate skills in the area of investigation, training and lack of working facilities. Although they had consensus on different techniques, they had variations on the application procedure, intensity and frequency. Cardiac Surgeons and Physiotherapists agreed that hospital management should motivate Physiotherapists by opening a Physiotherapy Unit within the Cardiac Complex and train Physiotherapists in the area of cardio-pulmonary. From these findings it can be concluded that, poor communication and lack of trained Physiotherapists in the field of cardio-pulmonary is a setback which need to be addressed. Also, lack of standard treatment procedure among Physiotherapists brings variations in this world of evidence based practice.