146 research outputs found

    Welcome to the 26th Annual Conference of the World Society of Cardiothoracic Surgery and the 17th Annual Congress of the South African Heart Association.

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    On behalf of the organising committee we would like to welcome you to the 26th Annual Conference of the World Society of Cardiothoracic Surgery. The conference is jointly hosted by the Society of Cardiothoracic Surgeons of South Africa and the South African Heart Association and will incorporate the Annual Conference of the SA Heart Association. We hope that the inclusion of both disciplines of cardiac surgery and cardiology will embellish the programme and give credence to, and embody, the concept of the Heart Team

    Digitized and computerized recordkeeping in dentistry (Orthodontics) : A Technologically Advanced Alternative to the Analysis and Storage of Study Models

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    Magister Scientiae Dentium - MSc(Dent)The research is aimed at investigating and finding alternatives to the physical necessity of producing and storing plaster casts or stone models of the tissues of the mouth. The quest for time and space is universal and the successful management of both results in stress free, financially stable and uncluttered work circumstances. Study models do playa very important role in diagnostics and treatment planning as well as communicating final results in Dentistry, especially in Orthodontic practice. Conventional study models are bulky, fragile, and expensive diagnostic tools produced from impressions taken of the patient's mouth and cast in plaster or stone. The storage of these records creates major space problems, and recalling or retrieving models at some later stage also causes logistical problems. Ideally, the tissues of the mouth could be scanned and from this a 3-D image produced on screen, which could later be milled (machining process of reproducing, explained in Appendix B) if necessary. Three dimensionally accurate, visually pleasing, reproducible, measurable and retrievable records, would be the solution. Computerizing dental records has already revolutionized the industry in the fields of Radiology and written patient data. This information is available at the click of a mouse, and integrated diagnostic tools can be displayed on screen. A thorough investigation of all methods of capturing dental data and 3D images from previously researched and publicized studies was conducted before attempting the latest technology. The final project involved: 1. requesting an introductory and explanatory demonstration on the scanning possibilities in South Africa 2. organizing and attending a demonstration of the laser and contact scanner on study models and impressions. 3. undergoing training in the use of a contact scanner. Computerizing of these results and comparing data derived from analyzing both study models and impressions, manually and digitally. 4. researching and collecting of data with engineering professionals, to establish the validity and viability of this method ( aiming to use uncomplicated, widely accepted and thoroughly applicable basic criteria in all experiments.) 5. evaluation of data statistically by a statistician. Discussion: Digitizing and computerizing of images derived from scanning the models or impressions offers the most attractive alternative for record keeping. Laser scanning disappointed in general due to the relative unavailability in South Africa, the expensive nature of the service elsewhere and limiting factors due to the sensitivity of the laser beam. It is the most promising alternative in future research, because of improved accuracy, higher speed of scanning, uniformity and reproducibility. Contact scanning proved to be available, reliable and adjustable. In most applications, the best results in terms of accuracy and quality of surface finish are obtained using contact scanning. The disadvantage of this method is the time factor and therefore it becomes expensive and economically not viable. The direct scanning of impressions, albeit with laser or contact scanning, remains a scientific and clinical viable option. Conclusion: Digital imaging is still a young technology and many aspects are not yet completely explored. It is a promising technology and its significance is increasing because it opens the door to diagnostic information. Another important development is that the software for digital imaging will become more integrated with other computerized dental applications in the dental office, enabling patient data between different and remote practices to be exchanged more easily. Further progress is not limited by a lack of available image processing tools but rather by our restricted understanding of the various components of diagnostic imaging in dentistry. A Bioengineering exhibition mounted by the University of Munich during a December 2000 conference, displayed a specially adapted CT Scanner that could scan information directly from the mouth. This leads to more possibilities of deriving images without impressions or study casts

    A review of cardiac tumors

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    The intention of the review is to highlight the clinical presentation and established surgical technique in the management of this relatively uncommon cardiac pathology. Intracardiac masses may be encountered by a cardiologist or cardiac surgeon, and a comprehensive knowledge of the various diagnostic modalities is therefore essential. More crucial are the likely probabilities, based on an amalgamation of the clinical features, echocardiographic and radiographic findings. If surgical management is undertaken, the intra-operative finding is ultimately correlated with the histopathological diagnosis. In the review, we emphasise the necessity of a multidisciplinary approach to management of these tumors. The cumulative experience of the various members of the team collectively enables increasingly accurate diagnoses to be made preoperatively, with appropriate surgical management carried out timeously

    Joint consensus statement and guideline on transcatheter aortic valve implantation (TAVI) in South Africa

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    The South African Heart Association (SA Heart) together with its major special interest groups, SASCI and SCTSSA represent the scientific, educational, socio-economic, ethical and professional interest of cardiac specialists, with a combined membership of over 200 members: We are the only national organisations exclusively representing practicing cardiologists and cardiothoracic surgeons. We are dedicated to maintain the highest standards of practice for our specialists and the highest quality of care for patients who require our care. As a result, we seek to serve as a knowledge resource for patients and funders in matters related to new technology used in our disciplines

    Effects of Physical Exercise Training on Cerebral Blood Flow Measurements:A Systematic Review of Human Intervention Studies

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    The aim of this systematic review was to examine the effects of physical exercise training on cerebral blood flow (CBF), which is a physiological marker of cerebrovascular function. Relationships between training-induced effects on CBF with changes in cognitive performance were also discussed. A systematic search was performed up to July 2022. Forty-five intervention studies with experimental, quasi-experimental, or pre-post designs were included. Sixteen studies (median duration: 14 weeks) investigated effects of physical exercise training on CBF markers using magnetic resonance imaging, 20 studies (median duration: 14 weeks) used transcranial Doppler ultrasound, and eight studies (median duration: 8 weeks) used near-infrared spectroscopy. Studies using magnetic resonance imaging observed consistent increases in CBF in the anterior cingulate cortex and hippocampus, but not in whole-brain CBF. Effects on resting CBF-measured with transcranial Doppler ultrasound and near-infrared spectroscopy-were variable, while middle cerebral artery blood flow velocity increased in some studies following exercise or hypercapnic stimuli. Interestingly, concomitant changes in physical fitness and regional CBF were observed, while a relation between training-induced effects on CBF and cognitive performance was evident. In conclusion, exercise training improved cerebrovascular function because regional CBF was changed. Studies are however still needed to establish whether exercise-induced improvements in CBF are sustained over longer periods of time and underlie the observed beneficial effects on cognitive performance.</p

    Thinner Regions of Intracranial Aneurysm Wall Correlate with Regions of Higher Wall Shear Stress: A 7T MRI Study

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    BACKGROUND AND PURPOSE: Both hemodynamics and aneurysm wall thickness are important parameters in aneurysm pathophysiology. Our aim was to develop a method for semi-quantitative wall thickness assessment on in vivo 7T MR images of intracranial aneurysms for studying the relation between apparent aneurysm wall thickness and wall shear stress. MATERIALS AND METHODS: Wall thickness was analyzed in 11 unruptured aneurysms in 9 patients who underwent 7T MR imaging with a TSE-based vessel wall sequence (0.8-mm isotropic resolution). A custom analysis program determined the in vivo aneurysm wall intensities, which were normalized to the signal of nearby brain tissue and were used as measures of apparent wall thickness. Spatial wall thickness variation was determined as the interquartile range in apparent wall thickness (the middle 50% of the apparent wall thickness range). Wall shear stress was determined by using phase-contrast MR imaging (0.5-mm isotropic resolution). We performed visual and statistical comparisons (Pearson correlation) to study the relation between wall thickness and wall shear stress. RESULTS: 3D colored apparent wall thickness maps of the aneurysms showed spatial apparent wall thickness variation, which ranged from 0.07 to 0.53, with a mean variation of 0.22 (a variation of 1.0 roughly means a wall thickness variation of 1 voxel [0.8 mm]). In all aneurysms, apparent wall thickness was inversely related to wall shear stress (mean correlation coefficient, −0.35; P < .05). CONCLUSIONS: A method was developed to measure the wall thickness semi-quantitatively, by using 7T MR imaging. An inverse correlation between wall shear stress and apparent wall thickness was determined. In future studies, this noninvasive method can be used to assess spatial wall thickness variation in relation to pathophysiologic processes such as aneurysm growth and rupture

    Aerobic exercise training improves not only brachial artery flow-mediated vasodilatation but also carotid artery reactivity: A randomized controlled, cross-over trial in older men.

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    It is well-known that aerobic exercise training beneficially affects endothelial function as measured by brachial artery flow-mediated vasodilation (FMD). This trial with older sedentary overweight and obese men, therefore, examined the effects of aerobic training on other non-invasive markers of the vasculature, which have been studied in less detail. Seventeen men (67 ± 2 years, BMI: 30.3 ± 2.8 kg/m2 ) participated in this controlled cross-over study. Study participants followed in random order a fully supervised, progressive, aerobic exercise training (three 50-min sessions each week at 70% maximal power) and a no-exercise control period for 8 weeks, separated by a 12-week wash-out period. At the end of each period, endothelial function was assessed by the carotid artery reactivity (CAR) response to a cold pressor test and FMD, and local carotid and regional aortic stiffness by the carotid-to-femoral pulse wave velocity (PWVc-f ). The retinal microvasculature, the serum lipid profile, 24-h ambulatory blood pressure, and 96-h continuous glucose concentrations were also determined. Aerobic training increased CAR from 1.78% to 4.01% (Δ2.23 percentage point [pp]; 95% CI: 0.58, 3.89 pp; p = 0.012) and FMD from 3.88% to 6.87% (Δ2.99 pp; 95% CI: 0.58, 5.41 pp; p = 0.019). The stiffness index β0 increased by 1.1 (95% CI: 0.3, 1.9; p = 0.012), while PWVc-f did not change. Retinal arteriolar width increased by 4 μm (95% CI: 0, 7 μm; p = 0.041). Office blood pressure decreased, but ambulatory blood pressure, and serum lipid and continuous glucose concentrations did not change. Aerobic exercise training improved endothelial function and retinal arteriolar width in older sedentary overweight and obese men, which may reduce cardiovascular risk
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