Browsing by Author "Doubell, A."

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    A statement of intent on the formation of the NCRP on Cardiovascular and Metabolic Disease: A new initiative to fight heart disease, stroke, diabetes and obesity in South Africa
    (2007) Mayosi, B.; Bryer, A.; Lambert, V.; Levitt, N.; Noakes, T.; Ntsekhe, M.; Opie, L.; Rayner, B.; Zilla, P.; Abrahams, Z.; Abram, M.; Bhagwandin, N.; Bradshaw, D.; Dhansay, A.; Mbewu, A.; Madela-Mntla, N.; Parker, W-A.; Sifunda, S.; Skepu, A.; Steyn, N.; Brown, S.; Mollentze, W.; Brink, P.; Doubell, A.; Hough, S.; Huisamen, B.; Lochner, A.; Moolman-Smook, J.; Reuter, H.; Green-Thompson, W.; Horrocks, J.; Manga, P.; Norris, S.; Norton, G.; Raal, D.; Sliwa, K.; Woodiwiss, A.; Mntla, P.; Motala, A.; Naidoo, D.; Seedat, Y.; Ntutela, S.; Puoane, T.; Schwartz, P.
    [No abstract available]
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    Evaluation of left ventricular enlargement in the lateral position of the chest using the Hoffman and Rigler sign
    (Clinics Cardiv Publishing, 2003-06) Freeman, V.; Mutatiri, C.; Pretorius, M.; Doubell, A.
    Objective: To evaluate left ventricular enlargement in the lateral projection of the chest using the Hoffman and Rigler sign. Background: The Hoffman and Rigler sign for determining left ventricular enlargement was suggested as early as 1965 before the routine use of echocardiography. Methods: We studied 136 patients who had had cardiac ultrasound and chest X-rays with lateral projections. We assessed left ventricular size on the lateral projection using the Hoffman and Rigler method (measurement A) and compared this measurement to the value obtained by cardiac ultrasound. The effect of right ventricular size on this measurement was also evaluated. Results: The average value of measurement A in all patients with echocardiographic evidence of left ventricular enlargement (LVED above 59 mm) was 19 mm (SD ± 4.03) (95% CI 17.96 to 20.04). Of the 48 patients with a normal size left ventricle on echocardiography, 25.58% had measurement A 18 mm and above, and 13.95% had a value 19 mm and above. Of the 19 patients with right ventricular enlargement (normal left ventricle) on echocardiography, 36.84% had measurement A 18 mm and above, whereas 21.05% had this value 19 mm and above. Measurement A in patients with left ventricular enlargement compared with those with right ventricular enlargement showed a significant difference (p < 0.05). Conclusions: When the crossing of the inferior vena cava and the left ventricle can be adequately visualised, the Hoffman and Rigler sign of evaluating left ventricular enlargement in the lateral projection of the chest is a valuable alternative where cardiac ultrasound is not readily available.
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    Patient profile of a tertiary obstetric-cardiac clinic
    (South African Heart Association, 2014) Van der Merwe, J. L.; Hall, D. R.; Herbst, P.; Doubell, A.
    Background: Cardiac disease is the most important medical cause of maternal mortality in South Africa. Management of women with cardiac disease in pregnancy is highly specialised and they should ideally be evaluated early in pregnancy and in a multidisciplinary fashion with the aim of formulating a perinatal management plan. In order to facilitate the efficient management of these patients in the context of a large tertiary hospital in South Africa a combined obstetric-cardiac (O-C) clinic was established at Tygerberg Academic Hospital (TBH) in 2010. Objective: The purpose of this review is to describe the patient profile of an obstetric-cardiac clinic in South Africa, specifically the TBH O-C clinic and to share the lessons learnt from establishing this clinic. Methods: Retrospective review performed at TBH, a referral centre in the Western Cape Province of South Africa. All women evaluated and/or managed at the Obstetric-Cardiac clinic between 10 August 2010 and 4 December 2012 were included. Results: There were 231 women, rheumatic heart disease (n=79; 34.2%) was the predominant cardiac disease followed by congenital heart disease (n=78; 33.8%), medical conditions (n=38; 16.4%) and previous peripartum cardiomyopathy (n=9; 3.9%). Eighty-two women (35.5%) were perceived to be extremely high risk and their entire pregnancies were managed in the Obstetric-Cardiac clinic. The most common RHD lesion was mitral regurgitation (34.2%) and mixed mitral valve disease (24.1%). The most frequent CHD was ventricular septal defects (n=27; 35%). Conclusions: The cardiac disease profile of patients seen at this obstetric-cardiac clinic in a South African tertiary hospital reflects a transition from the disease profile of a typical developing country (high burden of rheumatic heart disease) to the disease profile seen in a more developed country (high burden of congenital heart disease). This could indicate improved quality of socio-economic development and the health care system. The increasing complexity of cardiac pathology that has to be dealt with in pregnant patients presenting to a tertiary hospital requires close collaboration between the obstetrician, cardiologist, cardiac surgeon and anesthetist caring for these patients. A dedicated obstetric-cardiac clinic is a good model to utilise in a tertiary hospital when aiming to optimise the care of patients with cardiac disease in pregnancy.
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    Predictors of 1-year survival in South African transcatheter aortic valve implant candidates
    (Health & Medical Publishing Group, 2020) Liebenberg, J. J.; Doubell, A.; Van Wyk, J.; Kidd, M.; Mabin, T.; Weich, H.
    Background. Transcatheter aortic valve implantation (TAVI) has undergone rapid expansion internationally over the past 15 years. In view of resource constraints in developing countries, a major challenge in applying this technology lies in identifying patients most likely to benefit. The development of a risk prediction model for TAVI has proved elusive, with a reported area under the curve (AUC) of 0.6 - 0.65. The available models were developed in a First-World setting and may not be applicable to South Africa (SA). Objectives. To evaluate novel indicators and to develop a TAVI risk prediction model unique to the SA context. The current work represents the important initial steps of derivation cohort risk model development and internal validation. Methods. Seven-year experience with 244 successive TAVI implants in three centres in Western Cape Province, SA, was used to derive risk parameters. All outcomes are reported in accordance with the Valve Academic Research Consortium definitions. Multiple preprocedural variables were assessed for their impact on 1-year survival using univariate and multivariate models. Results. Factors found not to correlate with 1-year survival included age, renal function and aortic valve gradients. The commonly used surgical risk prediction models (Society of Thoracic Surgeons score and EuroSCORE) showed no correlation with outcomes. Factors found to correlate best with 1-year survival on multivariate analysis were preprocedural body mass index (BMI) (favouring higher BMI), preprocedural left ventricular end-diastolic dimension (LVED) and ejection fraction (EF) (favouring smaller LVED and higher EF), absence of atrial fibrillation, and three novel parameters: independent living, ability to drive a car, and independent food acquisition/cooking. Discriminant analysis of these factors yielded an AUC of 0.8 (95% confidence interval 0.7 - 0.9) to predict 1-year survival, with resubstitution sensitivities and specificities of 72% and 71%, respectively. Conclusions. Apart from existing predictors, we identified three novel risk predictors (independent living, ability to drive a car, and independent food acquisition/cooking) for 1-year survival in TAVI candidates. These novel parameters performed well in this early evaluation, with an AUC for predicting 1-year survival higher than the AUCs for many of the internationally derived parameters. The parameters are inexpensive and easy to obtain at the initial patient visit. If validated prospectively in external cohorts, they may be applicable to other resource-constrained environments.