published_or_final_version / Nursing Studies / Master / Master of Nursing

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No description available.

The purpose of this study was to operationalize the coronary care patient's concept of hope. Analysis of 25 subjects' responses to an open interview format suggested that the sample's definition of hope revolved around five categories. These categories were: 1) theistic beliefs: 2) knowledge that they would not die, require surgery, or experience pain; 3) a wish not to die; 4) a wish to get better; and, 5) confidence that they would get better. Furthermore, significant differences in: 1) the sample's definition of hope: 2) the feelings associated with admission to the coronary care unit: and, 3) the factors that positively influenced the sample's level of hope were directly related to the subject's age.

Chronic diabetic patients have a higher incidence of and mortality from cardiac disease. A wide spectrum of cardiac problems plague the chronic diabetic including coronary artery disease, congestive heart failure and diabetic cardiomyopathy. Cardiac disease in the diabetic is not simply due to accelerated atherosclerosis alone, but is also due to a combination of microangiopathy, autonomic neuropathy, and various other factors which produce biochemical, functional and structural alterations in the heart. Recently, cardiac function was studied in animals with experimentally-induced diabetes and cardiac-dysfunction was reported in acute as well as chronic phases of experimental diabetes. Since cardiac disease is a consequence of long-standing diabetes in diabetic patients, investigation of myocardial function at various time points after induction of experimental diabetes would yield information regarding the development and progression of cardiac dysfunction in diabetes. We. therefore investigated cardiac function and pharmacology in isolated perfused working hearts obtained from 7, 30, 100, 180, 240 and 360-day alloxan and streptozotocin (STZ) diabetic and age-matched control hearts. Diabetes was induced in the rat by injecting either alloxan (65 or 40 mg/kg) or STZ (50 or 60 mg/kg) into the tail vein. Diabetic and age-matched control rats were sacrificed at various time points after the induction of diabetes and hearts were isolated and perfused on a working heart apparatus. Cardiac function was studied at various left atrial filling pressures and was expressed in terms of left ventricular developed pressure (LVDP), rate of rise of left ventricular pressure (positive dP/dt) and rate of decline of left ventricular pressure (negative dP/dt). Dose-response curves to carbachol and isoproterenol were also performed. Blood samples were collected at the time of sacrifice, serum was separated and analyzed for insulin and glucose content. Both alloxan and STZ produced diabetes in the rat as shown by fasting hypoinsulinemia and hyperglycemia. Cardiac function was not altered in 7-day alloxan and STZ diabetic rats. Depressed function at various left atrial filling pressures was seen in hearts isolated from 30-day alloxan diabetic rats but not in 30-day STZ diabetic rats. Hearts isolated from 100-day alloxan and STZ diabetic rats, 180- and 360-day STZ diabetic rats and 240-day alloxan diabetic rats, all exhibited cardiac functional abnormalities. Cardiac functional abnormalities observed in d.iabetic rats were, depressed >LVOP and -positive«.and negative dP/dt at high left atrial filling pressures. Diabetic rat hearts exhibited no change in either sensitivity or responsiveness to the negative inotropic effect of carbachol at 7 and 30 days after induction of the disease. A sub-sensitivity to carbachol was observed in diabetic rat hearts at 100 days after induction of diabetes as compared to age-matched control rat hearts. However, 180- and 240-day diabetic rat hearts exhibited supersensitivity to the negative inotropic effect of carbachol. Isoproterenol produced an identical positive inotropic effect in control as well as diabetic rat hearts at all of the time points studied. However, the maximum changes produced by isoproterenol in negative dP/dt of diabetic rat hearts were depressed at various time points as compared to those in age-matched control rat hearts. We also studied the effect of isoproterenol on the cyclic AMP content and phosphorylase a activity in hearts obtained from 3 and 100 to 120 day control and diabetic rats. Basal cyclic AMP content and phosphorylase a activity were not altered in acute and chronic diabetic and age-matched control rat hearts. Isoproterenol produced similar time- and dose-dependent changes in cyclic AMP content and positive and negative dP/dt in isolated perfused working hearts obtained from 3 and 100 to 120 day control and diabetic rats. However, isoproterenol caused a significantly greater activation of phosphorylase enzyme in hearts isolated from 3 and 100 to 120 day diabetic rats as compared to age-matched controls. Diabetic rat hearts had a significantly higher total phosphorylase activity at 100 to 120 days as compared to age-matched controls. Prostaglandin E₁, a drug which increases cyclic AMP content without altering phosphorylase a activity in perfused rat hearts, increased phosphorylase a activity in acute as well as chronic diabetic rat hearts but not in control rat hearts. Cholinergic muscarinic receptors in the ventricles obtained from 180-day control and STZ diabetic rats were studied by performing radioligand binding studies. [³H]NMS was used as a radioligand to stereospecifically label all of the muscarinic receptor binding sites present in the ventricular membrane preparation. There was no change in either the receptor density or in the binding constants for antagonists and agonists at the muscarinic receptor site in 180-day diabetic rat hearts as compared to control. Ventricular noradrenaline content was estimated using an HPLC method, in 180-day alloxan and STZ diabetic and age-matched control rat hearts. There was no significant change in the noradrenaline content of diabetic rat hearts. Results obtained in the above studies demonstrate that various functional, pharmacological and biochemical alterations occur in the heart in experimental diabetes. Depressed cardiac performance was observed in isolated perfused diabetic rat hearts at various time points after the induction of diabetes and may represent the preclinical ventricular dysfunction phase of a developing diabetic cardiomyopathy. Changes noticed in the sensitivity of the.diabetic myocardium towards the negative inotropic effect of carbachol may represent various stages of a parasympathetic autonomic neuropathy of the heart in diabetes. The unaltered positive inotropic effect of Hsoproterenol and unchanged noradrenaline content in diabetic rat hearts indicate the absence of a sympathetic autonomic neuropathy. The depressed cardiac relaxant effect (maximum changes produced in negative dP/dt) of isoproterenol in diabetic rat hearts suggest defects in cardiac muscle relaxation, Ca²⁺ handling by the sarcoplasmic reticulum and perhaps ATP production and utilization. The enhanced sensitivity of the phosphorylase enzyme to agonists in diabetic rat hearts may be an outcome of alterations in Ca²⁺ homeostasis and other acute metabolic derangements in the heart caused by diabetes. All these changes could contribute to the pathogenesis of a diabetic cardiomyopathy. / Pharmaceutical Sciences, Faculty of / Graduate

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Progressive familial heart block type I (PFHBI) is a cardiac ventricular conduction disorder of unknown cause associated with risk of sudden death, which has been described in several South African families. Clinically, PFHBI is characterised by right bundle branch block on ECG, which may progress to complete heart block, necessitating pacemaker implantation. The disease shows an autosomal dominant pattern of inheritance with evidence of genetic anticipation. Using genetic linkage analysis, the PFHBI-causative gene was mapped to a 10 eentimorgan (cM) gene-rich area of chromosome (C) 19q13.3, which has, subsequently, been reduced to 7cM by fine mapping with polymorphic dinucleotide (CA)n short tandem repeat (STR) markers. Several attractive candidate genes, including muscle glycogen synthase (GSY 1) and histidine-rich calcium binding protein (HRC), lie within this region. The aim of the present study was two-fold: 1) to identify and characterise tetranucleotide (AAAT)n STRs within the PFHBI critical region that could be developed as polymorphic markers for use in genetic fine mapping and 2) to screen selected regions of GSY 1and HRC, positional candidate genes, for the presence ofPFHBI-causing mutation(s). Cosmids harbouring CI9q13.3 insert DNA were screened for the presence of (AAAT)n STRs by dot blot and Southern blot hybridisation using a radiolabelled (AAAT)lO oligonucleotide probe. To characterise the harboured (AAAT)n STRs, the positively hybridising fragments identified by Southern blot were sub-cloned, sequenced and primers designed from the unique repeat-flanking sequences. These primers were used to genotype the (AAAT)n repeat locus to assess its polymorphic nature in a panel of unrelated individuals. Alternatively, vectorette PCR, a rapid method of identifying repeat sequences and obtaining the flanking sequences in large inserts, was employed to develop polymorphic markers from the positively hybridising clones. Selected exons of GSY1 and HRC were screened for the presence of potentially disease-causing mutations by PCR-SSCP analysis and direct sequencing, respectively, in PFHBI-affected and unaffected family members. Of the available cosmid clones that gave strong signals on dot blot and Southern blot hybridisation, three, 29395, 24493 and 20381, were located within the critical PFHBI area and were used for marker development. An interrupted (AAAT)n repeat motif (n less than 5) was identified in cosmid 29395, however, the repeat locus was not polymorphic in the tested population. No (AAAT)n motif, single or repeated was observed in the partial sequence of the sub-cloned fragment of cosmid 24493. Using vectorette peR, no repeated (AAAT)n motif was identified on sequencing the generated products in either cosmid 24493 or 2038l. However, diffuse single AAAT motifs were detected in both cosmids. Exons 4, 5, 11, 12 and 16 of GSY 1, containing domains that are conserved across species, and the conserved eterminus- encoding exons 2-6 of HRC were selected for screening for potential PFHBI-causing mutation(s). However, no sequence variations were detected. The interrupted (AAAT)n repeat identified in cosmid 29395 was not polymorphic, which confirmed reports that complex repeats, especially those containing AAAT motifs of less than 6 repeats, are not polymorphic. One possible explanation for the absence of a repeated AAAT motif in cosmids 24493 and 20381, which both gave positive hybridisation signals, is that the low annealing temperature of the AfT -rich repeat-anchored primers used in vectorette peR may have resulted in transient annealing to the diffuse single AAAT motifs detected on sequencing. The screened regions of candidate genes GSYI and HRC were excluded from carrying the disease-causing mutation(s). The availability of new sequence data generated by the Human Genome Project will influence future strategies to identify the PFHBI gene. Electronic searches will allow identification of STR sequences for development of polymorphic markers and gene annotation will allow selection of new candidate genes for mutation screening. / AFRIKAANSE OPSOMMING: Sien volteks vir opsomming

Diss. Linköping : Linköpings universitet, 2004.

The aims of the present study were threefold: firstly, to further the understanding of the psychological response to heart disease; secondly, to consider the differences in the ways in which doctors and patients perceive heart disease; and thirdly, to consider how the doctor, patient, and condition interact within the illness process over a period of time. The nature of coronary heart disease (CHD) was considered, and the influence of psychological variables in CHD was discussed. Psychological factors in illness were examined, with particular emphasis on health beliefs, illness behaviour, compliance, and the doctor-patient relationship. Conclusions were drawn that to understand the illness process in heart disease, doctor, patient, and condition must be considered together, in an interactional framework. Two pilot studies were performed. The first study found that heart patients' health beliefs differed from a normal population. The second pilot study, with raised cholesterol patients, suggested the existence of five major components of the illness process: illness perception, illness effect, health orientation, doctor-patient relationship, and compliance. The main study considered groups of heart and cholesterol patients (experimental groups) and a group of general outpatients (control group), over a four-to-six month period. Patients were interviewed and given a questionnaire concerning their feelings regarding their condition. Doctors and judges also completed similar questionnaires. Results indicate that cholesterol patients rate superior coping to the other groups, and both experimental groups were higher than controls with regard to patient understanding, responsibility for health, and communication with doctor. Findings suggests alterations should be made in current conceptualization of illness behaviour. and that patient and doctor assessment of condition severity were found to be unrelated to illness behaviour. Doctor and patient perception of patient behaviour were found to be discrepant. Modifications in the treatment of heart and cholesterol patients are suggested.

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A descriptive design was utilized to identify the relationship between perceived cardiac rehabilitation at the time of discharge and perceived self-care three months later. Perceived cardiac rehabilitation was indicated by perceived quality of the cardiac rehabilitation program, perceived understanding of self-care, and satisfaction with hospital care. Perceived self-care was indicated by self-reported self-care related exercise, stress management, and medication. Fifty-three patients from a community hospital voluntarily participated in the study by responding to four questionnaires. A low positive relationship was found between (a) perceived quality of the cardiac rehabilitation program and self-reported stress management, (b) perceived understanding of self-care and self-reported exercise and stress management, and (c) satisfaction with hospital care and self-reported exercise and medication administration. These findings of post-hospital care are useful in the evaluation of the effectiveness of one nurse-coordinated cardiac rehabilitation program.