Browsing by Author "Herbst, Philip"
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- ItemThe hidden continuum of HIVassociated cardiomyopathy : a focussed review with case reports(South African Heart Association, 2021) Robbertse, Pieter-Paul; Doubell, Anton; Nachega, Jean; Herbst, PhilipENGLISH ABSTRACT: HIV-associated cardiomyopathy (HIVAC) is a poorly understood group of diseases with a poor prognosis once ventricular dysfunction is present. Cardiovascular magnetic resonance has revealed a previously unappreciated burden of asymptomatic myocardial abnormalities in people living with HIV, including abnormalities already present at the time of HIV diagnosis. These abnormalities include thickened, inflamed ventricles that bear resemblance to cases of symptomatic HIVAC that are reported on in this article. Our understanding and the significance of asymptomatic HIV-associated myocardial pathology will be explored as early disease on a continuum towards more advanced cardiomyopathy. The need for prospective research in persons naïve to anti-retroviral therapy is emphasised as it may provide key findings to better understand this elusive disease process.
- ItemPersistant left superior vena cava – the value of an agitated saline contrast study(South African Heart Association, 2014) Moses, Jane; Kyriakakis, Charles; Weich, Hellmuth; Rossouw, Pieter; Herbst, Philip; Doubell, AntonA persistant left superior vena cava (PLSVC) draining to the coronary sinus (CS) is the most common venous anomaly of the thorax, affecting approximately 0.5% - 2% of the general population, and is present in up to 10% of patients with other congenital cardiac anomalies.(1) The embryological development of the thoracic venous system is complex and subject to significant variation. Usually, most of the left cardinal system involutes, leaving only the coronary sinus, which drains the cardiac veins, and the ligament of Marshall (a remnant of the left superior vena cava).(2) The presence of a PLSVC is usually an incidental finding at either echocardiography, cardiac catheterisation or device implantation.(1) The typical echocardiographic findings are that of a dilated CS, which can be appreciated on the parasternal long axis view, the parasternal short axis at mitral valve level, the apical 2 chamber view and a modified apical four chamber view scanning down to visualise the CS (Figure 1). A contrast study with agitated saline (“bubble study”) done via the left brachial vein will demonstrate the dilated CS draining into the right atrium (Figure 2).
- ItemPROVE—Pre-Eclampsia Obstetric Adverse Events: Establishment of a Biobank and Database for Pre-Eclampsia(MDPI, 2021-04) Bergman, Lina; Bergman, Karl; Langenegger, Eduard; Moodley, Ashley; Griffith-Richards, Stephanie; Wikström, Johan; Hall, David; Joubert, Lloyd; Herbst, Philip; Schell, Sonja; Van Veen, Teelkien; Belfort, Michael; Tong, Stephen Y. C.; Walker, Susan; Hastie, Roxanne; Cluver, CatherinePre-eclampsia is a leading cause of maternal and perinatal morbidity and mortality. The burden of disease lies mainly in low-middle income countries. The aim of this project is to establish a pre-eclampsia biobank in South Africa to facilitate research in the field of pre-eclampsia with a focus on phenotyping severe disease.The approach of our biobank is to collect biological specimens, detailed clinical data, tests, and biophysical examinations, including magnetic resonance imaging (MRI) of the brain, MRI of the heart, transcranial Doppler, echocardiography, and cognitive function tests.Women diagnosed with pre-eclampsia and normotensive controls are enrolled in the biobank at admission to Tygerberg University Hospital (Cape Town, South Africa). Biological samples and clinical data are collected at inclusion/delivery and during the hospital stay. Special investigations as per above are performed in a subset of women. After two months, women are followed up by telephonic interviews. This project aims to establish a biobank and database for severe organ complications of pre-eclampsia in a low-middle income country where the incidence of pre-eclampsia with organ complications is high. The study integrates different methods to investigate pre-eclampsia, focusing on improved understanding of pathophysiology, prediction of organ complications, and potentially future drug evaluation and discovery.
- ItemRedefining effusive-constrictive pericarditis with echocardiography(Korean Society of Journal of Cardiovascular Ultrasound Office, 2016-12) Van der Bijl, Pieter; Herbst, Philip; Doubell, Anton F.Background: Effusive-constrictive pericarditis (ECP) is traditionally diagnosed by using the expensive and invasive technique of direct pressure measurements in the pericardial space and the right atrium. The aim of this study was to assess the diagnostic role of echocardiography in tuberculous ECP. Methods: Intrapericardial and right atrial pressures were measured pre- and post-pericardiocentesis, and right ventricular and left ventricular pressures were measured post-pericardiocentesis in patients with tuberculous pericardial effusions. Echocardiography was performed post-pericardiocentesis. Traditional, pressure-based diagnostic criteria were compared with post-pericardiocentesis systolic discordance and echocardiographic evidence of constriction. Results: Thirty-two patients with tuberculous pericardial disease were included. Sixteen had ventricular discordance (invasively measured), 16 had ECP as measured by intrapericardial and right atrial invasive pressure measurements and 17 had ECP determined echocardiographically. The sensitivity and specificity of pressure-guided measurements (compared with discordance) for the diagnosis of ECP were both 56%. The positive and negative predictive values were both 56%. The sensitivity of echocardiography (compared with discordance) for the diagnosis of ECP was 81% and the specificity 75%, while the positive and the negative predictive values were 76% and 80%, respectively. Conclusion: Echocardiography shows a better diagnostic performance than invasive, pressure-based measurements for the diagnosis of ECP when both these techniques are compared with the gold standard of invasively measured systolic discordance.
- ItemA retrospective analysis of mitral valve pathology in the setting of bicuspid aortic valves(BioScientifica, 2017) Van Rensburg, Annari; Herbst, Philip; Doubell, AntonThe therapeutic implications of bicuspid aortic valve associations have come under scrutiny in the transcatheter aortic valve implantation era. We evaluate the spectrum of mitral valve disease in patients with bicuspid aortic valves to determine the need for closer echocardiographic scrutiny/follow-up of the mitral valve. A retrospective analysis of echocardiograms done at a referral hospital over five years was conducted in patients with bicuspid aortic valves with special attention to congenital abnormalities of the mitral valve. One hundred and forty patients with a bicuspid aortic valve were included. A congenital mitral valve abnormality was present in eight (5.7%, P = 0.01) with a parachute mitral valve in four (2.8%), an accessory mitral valve leaflet in one (0.7%), mitral valve prolapse in one, a cleft in one and the novel finding of a trileaflet mitral valve in one. Minor abnormalities included an elongated anterior mitral valve leaflet (P < 0.001), the increased incidence of physiological mitral regurgitation (P < 0.001), abnormal papillary muscles (P = 0.002) and an additional chord or tendon in the left ventricle cavity (P = 0.007). Mitral valve abnormalities occur more commonly in patients with bicuspid aortic valves than matched healthy individuals. The study confirms that abnormalities in these patients extend beyond the aorta. These abnormalities did not have a significant functional effect.
- ItemRheumatic heart disease screening : current concepts and challenges(Medknow Publications, 2017) Dougherty, Scott; Khorsandi, Maziar; Herbst, PhilipRheumatic heart disease (RHD) is a disease of poverty, is almost entirely preventable, and is the most common cardiovascular disease worldwide in those under 25 years. RHD is caused by acute rheumatic fever (ARF) which typically results in cumulative valvular lesions that may present clinically after a number of years of subclinical disease. Therapeutic interventions, therefore, typically focus on preventing subsequent ARF episodes (with penicillin prophylaxis). However, not all patients with ARF develop symptoms and not all symptomatic cases present to a physician or are correctly diagnosed. Therefore, if we hope to control ARF and RHD at the population level, we need a more reliable discriminator of subclinical disease. Recent studies have examined the utility of echocardiographic screening, which is far superior to auscultation at detecting RHD. However, there are many concerns surrounding this approach. Despite the introduction of the World Heart Federation diagnostic criteria in 2012, we still do not really know what constitutes the most subtle changes of RHD by echocardiography. This poses serious problems regarding whom to treat and what to do with the rest, both important decisions with widespread implications for already stretched health-care systems. In addition, issues ranging from improving the uptake of penicillin prophylaxis in ARF/RHD-positive patients, improving portable echocardiographic equipment, understanding the natural history of subclinical RHD and how it might respond to penicillin, and developing simplified diagnostic criteria that can be applied by nonexperts, all need to be effectively tackled before routine widespread screening for RHD can be endorsed.
- ItemScreening for asymptomatic rheumatic heart disease : understanding the mechanisms key to the diagnostic criteria(South African Heart Association, 2015) Herbst, PhilipThis focussed review describes important problems experienced in the world of echocardiographic screening for asymptomatic rheumatic heart disease (RHD). It offers a critical appraisal of the screening criteria and their application and explores some of the fundamental principles underpinning the shortcomings of individual criteria. The author illustrates important mechanisms that underlie the morphological changes seen in RHD that must be accounted for if these criteria are to be rationalised and improved upon.
- ItemTri-leaflet mitral valves – when lightning strikes thrice(South African Heart Association, 2016) Van Rensburg, Annari; Pecoraro, Alfonso; Kyriakakis, Charles; Herbst, Philip; Doubell, AntonENGLISH ABSTRACT: Mitral valves are well known to be bi-leaflet structures with attachments from both leaflets (anterior and posterior) to both papillary muscles (anterolateral and posteromedial). Congenital abnormalities of the mitral valve, although well described, are quite rare. These abnormalities can involve either the leaflet (cleft mitral valve) or the subvalvular apparatus (parachute mitral valve) or even occur as accessory mitral valve tissue (accessory mitral valve leaflet). These can occur in isolation, or in association with other congenital abnormalities. A tri-leaflet mitral valve is a novel echocardiographic finding that has only been described in 6 patients in 4 different case reports.(1-4) We report on 3 patients recently found to have trileaflet mitral valves in the setting of atrioventricular concordance and normal offset of the AV valves at our out-patient clinic.
- ItemWhen opportunity knocks(South African Heart Association, 2016) Van Rensburg, Annari; Kyriakakis, Charles; Pecoraro, Alfonso; Herbst, PhilipENGLISH ABSTRACT: Constrictive pericarditis remains a common medical problem in developing countries where it frequently complicates tuberculous pericarditis. In addition, it is not infrequently seen in the developed world in the context of previous cardiac surgery, chest irradiation and even idiopathic pericarditis.(1) The diagnosis of pericardial constriction is often elusive and delays between the onset of symptoms and final diagnosis is the norm. Given the potential curability of this cause of heart failure and the fact that various features of chronicity in the disease portend a poor prognosis, recognising the disease early is of paramount importance.(1) The haemodynamics of constriction, particularly in more pronounced cases, produces a set of interesting clinical findings that the vigilant physician can elicit. A useful, and often neglected clinical feature, is that of a diastolic precordial or epigastric impulse, the palpable equivalent of an audible diastolic pericardial knock. This short report illustrates this unique clinical finding and explains the haemodynamics responsible for it. We also briefly review other commonly found clinical findings that assist in making the diagnosis of constrictive pericarditis.