SUNScholar - Browsing by Author "Doubell, A. F."

Browsing by Author "Doubell, A. F."

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Evaluation of the SUNHEART cardiology outreach programme
(South African Heart Association, 2015) Van Deventer, J. D.; Doubell, A. F.; Herbst, P. G.; Piek, H.; Piek, C.; Marcos, E.; Pecoraro, A. J. K.
Introduction: The demand for advanced cardiac care and specialised interventions is on the increase and this results in bottlenecks and increased waiting times for patients who require advanced cardiac care. By decentralising cardiac care, and using a hub-and-spoke model, the SUNHEART Outreach Programme of cardiovascular care aims to improve access to advanced cardiac care in the Western Cape. Tygerberg Hospital is the central hub, with the fi rst spoke being Paarl Hospital. Objective: To determine the value of the SUNHEART Outreach Programme to the public health care system. Methods: An audit of patients accessing the Outreach Programme was performed for the period May 2013 - May 2014 and consequently compared to a historical cohort of patients accessing the health care system during the preceding 6 months, from October 2012 - April 2013. Access to advanced cardiac care was measured in time to initial evaluation, time to defi nitive diagnosis or intervention and patient compliance with appointments. The value to the health care system was also assessed by performing a cost analysis of transport of patients and health care workers, as well as compliance with appointments. We documented the spectrum of disease requiring advanced cardiac care to guide future interventions. Results: Data of 185 patients were included in the audit. Sixty four patients were referred to tertiary care from October 2012 - April 2013 and 121 patients were referred to the outreach facility from May 2013 - May 2014. There was a signifi cant reduction in waiting times with the median days to appointment of the historical cohort being 85 days compared to 18 days in the Outreach Programme cohort (p<0.01). Patient compliance with appointments was signifi cantly superior in the Outreach Programme cohort (90% vs. 56%: p<0.01). Valvular (36.5%) and ischaemic heart disease (35.5%) were the major pathologies requiring access to cardiac care services. Transport costs per patient treated was signifi cantly reduced in the outreach programme cohort (R118,09 vs. R308,77). Conclusion: Decentralisation of services in the form of an Outreach Programme, with a central hub, improves access to advanced cardiac care by decreasing waiting time, improving compliance with appointments and decreasing travel costs.
Ewart's sign in tuberculous pericarditis
(Health & Medical Publishing Group, 2000) Smedema, J. P.; Katjitae, I.; Reuter, H.; Doubell, A. F.
[No abstract available]
Inter-scallop separations of the posterior leaflet of the mitral valve : an important cause of pathological mitral regurgitation in rheumatic heart disease screening
(BioScientifica, 2018) Hunter, L. D.; Monaghan, M.; Lloyd, G.; Pecoraro, A. J. K.; Doubell, A. F.; Herbst, P. G.
The 2012 World Heart Federation (WHF) criteria for echocardiographic diagnosis of rheumatic heart disease (RHD) identify that the finding of ‘pathological’ mitral regurgitation (MR) in a screened individual increases the likelihood of detecting underlying RHD. Cases of isolated ‘pathological MR’ are thus identified as ‘borderline RHD’. A large-scale echocardiographic screening program (Echo in Africa) in South Africa has identified that inter-scallop separations of the posterior mitral valve leaflet (PMVL) can give rise to ‘pathological’ MR. The authors propose that this entity in isolation should be identified and excluded from the WHF ‘borderline RHD’ category. In this case report, we present two examples of ‘pathological’ MR related to inter-scallop separation from the Echo in Africa image database. We further provide screening tips for the accurate identification of this entity.
Mitral valve apparatus : echocardiographic features predicting the outcome of percutaneous mitral balloon valvotomy
(Clinics Cardiv Publishing, 2007-06) Du Toit, R.; Brice, E. A. W.; Van Niekerk, J. D.; Doubell, A. F.
Objectives: To evaluate the significance of involvement of subvalvular apparatus in the outcome of percutaneous mitral balloon valvotomy (PMBV) in patients with mitral stenosis (MS) and to determine the predictive value of chordal length compared with current echocardiographic scores. Methods: Patients with significant MS were selected according to the Massachusetts General Hospital score (MGHS). Chordal lengths were assessed as additional markers of disease. Standard percutaneous valvotomies were performed. Valve area was assessed post-procedure with follow-up over one year. Results: Thirty-nine patients were prospectively studied. Valve area increased from a mean (SD) 0.97 (0.26) cm² to 1.52 (0.38) cm² with procedural success in 31 (79.5%) patients. There was no correlation (r = 0.09) between the MGHS and final valve area (FVA). There was a positive correlation between anterior chordal length and FVA (r = 0.66; p = 0.01). An FVA ≥ 1.5 cm² was associated with higher mean chordal lengths (p = 0.01). A positive correlation was seen between valve area pre-procedure and FVA (r = 0.61; p < 0.01). Conclusions: The MGHS is valuable in the selection of patients for PMBV, but fails to separate selected patients into prognostic groups. Assessment of chordal length provides useful additional information, predicting the outcome of PMBV more accurately. Our data may support the earlier use of PMBV (asymptomatic patients).
Post-pulmonary tuberculosis complications in South Africa and a potential link with pulmonary hypertension : premise for clinical and scientific investigations
(Health & Medical Publishing Group, 2018) Allwood, Brian W.; Maarman, G. J.; Kyriakakis, C. G.; Doubell, A. F.
The magnitude of the pulmonary tuberculosis (TB) epidemic in South Africa (SA) and globally[1] has received increased attention. Efforts have been made to explore new and improved diagnostic[2] and treatment strategies,[3] but the story does not end with treatment, and TB frequently results in long-term lung damage.
Prosthetic valve obstruction at Tygerberg Hospital between January 1991 and February 2001
(Clinics Cardiv Publishing, 2003-08) Taljaard, J. J.; Doubell, A. F.
Background: Prosthetic valve obstruction is a relatively rare, but potentially fatal complication in patients with prosthetic heart valves. The diagnosis and appropriate management of these patients present a challenge to both the cardiologist and the cardiac surgeon. Despite efforts over the last 30 years to prevent this complication, it remains a lifelong risk. Obstruction is caused by pannus formation, thrombus formation or a combination of pannus and thrombus. Valve replacement has traditionally been the treatment of choice. Methods: Patients were selected from echocardiography and surgical reports between January 1991 and February 2001. All patients were analysed with regard to demographic information, clinical features, imaging results, treatment and outcome data. INR values on presentation were obtained from haematology archives. Results: A total of 32 patients presented on 34 occasions. There were 25 women and seven men. Obstruction occurred in the mitral position in 56% of cases and in the aortic position in 44% of cases. All but two valves were St Jude bileaflet valves. Patients generally presented with severe dyspnoea (NYHA class IV in 64.7%) and poor anticoagulation control (INR < 2.5 in 75.8%). The initial imaging modality used in all cases was transthoracic echocardiography. Fluoroscopy was used in five cases and transesophageal echocardiography in only two cases. Valve replacement was performed on 20 patients, six patients received thrombolysis and the remaining eight patients did not receive any treatment. Outcome was poor with an overall mortality of 64.7%. Conclusions: Given the extremely high mortality rate with current management, the treatment of prosthetic valve obstruction with thrombolysis in selected patients deserves consideration in a prospective study.
A retrospective audit of mitral valve repair surgery at Tygerberg Hospital
(South African Heart Association, 2018) Al Naili, M.; Herbst, P. G.; Doubell, A. F.; Janson, J. J.; Pecoraro, A. J. K.
Background: Mitral valve repair is well established as the preferred treatment modality for the majority of patients with degenerative mitral valve disease requiring intervention. Valve repair offers a distinct event-free survival advantage compared with replacement with either a bioprosthetic or mechanical valve. At present, there are little data available on the management and outcome of mitral valve repair in South Africa. The aim of this study is to describe and compare the indications, specific pathology and outcomes of patients accepted for mitral valve repair. Internationally published figures for peri-operative mortality are less than 2% for degenerative mitral regurgitation, with a freedom from mitral valve reoperation of 94% at 10 years. Methods: All patients referred for mitral valve repair at Tygerberg Hospital, Cape Town, South Africa, between 1 December 2010 and 30 June 2015, were retrospectively included. Demographic characteristics, cardiovascular risk factors, pre-operative (NYHA) functional class, the pre- and post-operative transthoracic and transoesophageal echocardiograms, immediate in hospital mortality and 6-month post-surgical mortality and functional class were analysed. Repair failure was defined as either intra-operative conversion to MVR or need for reoperation at 6 months. Results: A total of 147 patients were referred for mitral valve repair, of which 114 patients were accepted for mitral valve repair by the local heart team. In total, 106 of the 114 patients underwent surgical intervention, 6 defaulted their surgical dates, and 2 refused surgery. Of those accepted for surgery, 57.9% were males, 42.1% were females, with a mean age of 47.7 years in both groups combined, 44.7% had hypertension, 43.9% were smokers and 21.1% had concomitant IHD; 56.1% were pre-operative NYHA functional class III, 29.8% were class II, 7% class IV, and 7% were class I; 60.2% had a 6-month post-operative NYHA functional class I, 32.3% had class II, 5.4% class III, and 2.2% had class IV. Mitral valve prolapse (MVP) with flail segment due to chord rupture was the predominant etiology (29%); P2 was the most common segment involved (36%), followed by A2 (29.8%). For MVP, including patients with infective endocarditis, the mortality rate was 4.8% at 30 days and 6 months. The overall mortality rates for all patients accepted for mitral valve repair were 4.7% and 6.6% at 30 days and 6 months respectively. Freedom from reoperation was 98% at 6 months. There was a significant association between bileaflet involvement and mitral valve repair failure (p=0.006). Chordal insertion with annuloplasty was the most common intervention used (45.5%). Conclusion: Mitral valve prolapse was the predominant etiology in patients referred for mitral valve repair. The mortality rate for mitral valve repair in the prolapse group was 4.8% at 6 months. Chordal insertion with annuloplasty was the most common intervention used. Bileaflet involvement was found to be an independent risk factor for repair failure. The mortality rate for all patients accepted for mitral valve repair was 6.6% at 6 months.
The role of the endothelium in the reduction of restenosis following balloon angioplasty
(Clinics Cardive Publishing, 1998-10) Davids, MR; Page, C.; Muller, C. J.; Rossouw, D. J.; Doubell, A. F.
Objective. Coronary angioplasty is complicated in one-third of cases by restenosis due to intimal hyperplasia. This is the result of the migration and proliferation of vascular smooth-muscle cells (SMCs) and correlates with the extent of endothelial stripping. To study the effect of rapid re-endothelialisation on preventing intimal hyperplasia, a model of vessel injury is needed which allows for the retention and adhesion of cultured vascular endothelial cells (VECs) in the injured segment. Methods. The abdominal aortas of BD9 rats were injured with an embolectomy catheter and the response to injury assessed on days 1, 3, 7, 14 and 28. Cultured vascular endothelial cells (VECs) were then placed into injured vessels. Introduction of 51Cr-labelled cells was used first-to confirm adhesion, and then unlabelled cells were used to study the effect on intimal hyperplasia. Results. Medial necrosis and complete stripping of the endothelium was seen on days 1 and 3. By day 7 all rats had VECs lining part of the lumen. Intimal hyperplasia was present by day 14. Complete restitution of the endothelium was present at day 28 and medial SMC numbers were also back to normal at this time. Cells producing the intimal hyperplasia were identified as SMCs by staining for smooth-muscle actin and electron microscopy. Re-endothelialisation was confirmed by autoradiography following introduction of 51Cr-labelled VECs. In animals receiving VECs after injury (N = 15), intimal hyperplasia involved a smaller percentage of the lumen circumference compared with controls (N = 15), where only medium was introduced (52.00 ± 6.83% v. 63.47 ± 6.39%; P = 0.03). Conclusion. The response to balloon-induced injury in the rat aorta has been well characterised. This model enabled us to repopulate a damaged vessel with cultured VECs, resulting in a decrease in intimal hyperplasia.
Screening for rheumatic heart disease : is a paradigm shift required?
(BioScientifica, 2017) Hunter, L. D.; Monaghan, M.; Lloyd, G.; Pecoraro, A. J. K.; Doubell, A. F.; Herbst, P. G.
This focused review presents a critical appraisal of the World Heart Federation criteria for the echocardiographic diagnosis of rheumatic heart disease (RHD) and its performance in African RHD screening programmes. It identifies various logistical and methodological problems that negatively influence the current guideline’s performance. The authors explore novel RHD screening methodology that could address some of these shortcomings and if proven to be of merit, would require a paradigm shift in the approach to the echocardiographic diagnosis of subclinical RHD.

Browsing by Author "Doubell, A. F."

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