Evidence against a myocardial factor as the cause of left ventricular dilation in active rheumatic carditis

AbstractObjectives. The aim of this study was to determine whether left ventricular dilation and congestive heart failure in patients with acute rheumatic fever with carditis are accompanied by left ventricular contractile dysfunction.Background. Acute rheumatic fever with carditis involves both the myocardium and endocardium, with consequent valvular regurgitation. The relative contribution of volume overload induced by valvular regurgitation and myocardial dysfunction due to rheumatic myocarditis to the overall degree of left ventricular dilation and congestive heart failure in these patients is unknown.Methods. To investigate this, we evaluated 32 patients (15 male, 17 female, mean age 14 ± 3 years) with documented active carditis and congestive heart failure. All 32 patients were found to have significant isolated mitral regurgitation or combined mitral and aortic regurgitation. Echocardiographic analysis of left ventricular dimensions and systolic performance was performed before and after isolated mitral or combined mitral and aortic valve replacement and the results were compared with those in 19 control subjects matched for age, gender and body surface area.Results. Both preoperative left ventricular end-diastolic diameter and percent fractional shortening were significantly increased in patients compared with control subjects (57 ± 7 vs. 43 ± 3 mm, p < 0.001, and 38 ± 6% vs. 33 ± 1%, p < 0.001, respectively). After valve replacement, left ventricular end-diastolic diameter decreased significantly (57 ± 7 to 47 ± 6 mm, p < 0.001). Although percent fractional shortening decreased significantly postoperatively (38 ± 6% to 32 ± 6%, p < 0.001), the postoperative percent fractional shortening did not differ from that in control subjects (32 ± 6% vs. 33 ± 1%, p = NS).Conclusions. The results of this study indicate that left ventricular dilation and heart failure in patients with acute rheumatic carditis rarely occur in the absence of hemodynamically significant regurgitant valve lesions. Furthermore, rapid reduction in left ventricular dimensions and preservation of fractional shortening after isolated mitral or combined mitral and aortic valve replacement suggest that rheumatic carditis is not accompanied by any significant degree of myocardial contractile dysfunction

Coronary artery disease prevalence amongst patients undergoing valve replacement surgery: A South African perspective

Background: The prevalence of coronary artery disease (CAD) amongst patients presented for valve surgery has important implications for routine angiography. Information on the frequency of CAD in predominantly black patients presented for valve surgery in South Africa has not been published.Methods: A retrospective, descriptive study of 116 patients presented for valve surgery that underwent coronary angiography between 2010 and 2011 was performed. CAD was defined as stenosis of 70% or greater in one or more epicardial vessels or ≥50% in the left main coronary artery, as defined by quantitative coronary angiography.Results: Median age was 57.4 (IQR 43 - 67) years (56.9% females). Black patients represented 66.4%, whites 19.8%, and, coloured and Indian patients 13.8%. Hypertension and smoking were the most common cardiovascular risk factors (26.7% and 16.4% respectively). Diabetes mellitus, dyslipidaemia, chronic kidney disease and prior CAD occurred collectively in 15.5% of study subjects. HIV prevalence was 12%, half of whom were on antiretroviral therapy. An isolated valve lesion occurred in 69% of patients, with the remainder having 2 or more lesions. The most common valve lesion was aortic stenosis (43.1%), followed by mitral stenosis (36.2%), aortic regurgitation (29.3%), mitral regurgitation (25.9%) and tricuspid regurgitation (19%). The predominant aetiology was rheumatic heart disease (58.6%), followed by degenerative valve disease (24.1%). CAD was documented in 10 patients (8.6%), of whom 8 had single vessel disease and 2 had double vessel disease.Conclusion: The low prevalence of CAD found in younger, asymptomatic black patients without cardiovascular risk factors referred for valve surgery, raises the question of whether routine pre-operative coronary angiography in this sub-group is appropriate

Striking increase in the incidence of infective endocarditis associated with recreational drug abuse in urban South Africa

Background. We have recently noted a dramatic rise in the number of patients with infective endocarditis (IE) related to intravenous (IV) nyaope (a mixture of heroin, cocaine and antiretroviral drugs) presenting to Chris Hani Baragwanath Academic Hospital in Johannesburg, South Africa.Objectives. To document the clinical and echocardiographic characteristics of these patients.Methods. Clinical and echocardiographic characteristics of all patients (N=68) with IE due to IV nyaope use were retrospectively extracted from hospital records (December 2014 - February 2017).Results. The mean (standard deviation) age of the patients was 25.8 (4.5) years (97.1% were male). Withdrawal symptoms were noted in 25.1% of cases, fever in 58.8%, dyspnoea in 86.7% and right ventricular failure in 42.6%. Most patients were HIV-positive (76.1%), with CD4+ cell counts of &lt;200 cells/µL in 8.8% of the total, 58.1% had hepatitis C infection, and only three were on antiretrovirals. Septic pulmonary emboli were noted in 61.8%. Blood cultures revealed Staphylococcus aureus in 61.2%, Enterococcus faecalis in 8.8% and Pseudomonas aeruginosa in 1 patient; 29.2% had sterile cultures and 8.8% polymicrobial infection. Severe right ventricular systolic dysfunction (RVS' Doppler velocity &lt;10 cm/s) and pulmonary hypertension were noted in 19.1% and 62.2% of patients, respectively. Pericardial effusion was noted in 37.8%. The most commonly involved valve was the tricuspid (60.1%), followed by the mitral (17.2%), aortic (2.9%) and pulmonary (1 patient) valves. Combined valve lesions were noted in 19.1% of patients. Ten patients (14.7%) died. The main predictor of in-hospital mortality was S. aureus infection (odds ratio 5.0; p=0.042).Conclusions. We have documented the common clinical and echocardiographic characteristics of patients with IE secondary to IV nyaope use. IE due to IV drug use is responsible for considerable morbidity and mortality in a predominantly young male population. 

The effects of benfotiamine in attenuating hyperglycemia-induced cardiac pathology

Type 2 diabetes is a major global health problem. It is also a risk factor for the onset of cardiovascular diseases, the current leading cause of global mortality. The first part of this mini-review describes hyperglycemia-induced cellular alterations and its effects on cardiac function. In particular, we emphasize the role of hyperglycemia-induced oxidative stress in the activation of non-oxidative glucose pathways (NOGPs), that may contribute to cardiac pathology. For the second part, we evaluate the utility of benfotiamine (a vitamin B1 derivative) in treating diabetes-related cardiac pathology. The focus is on its role in activating the pentose phosphate pathway, which may reduce flux though the NOGPs. A possible role for benfotiamine in activating pro-survival signaling and reducing cell death in the heart is also described. We also discuss benfotiamine’s potential cardioprotective role in preventing the diabetic cardiomyopathy, treating myocardial infarction and maintaining the viability of cardiac progenitor cells. These findings warrant further investigation into the therapeutic potential of benfotiamine in treating diabetes-related cardiac complications.Keywords: Diabetes; cardiovascular disease; hyperglycemia; oxidative stress; non-oxidative glucose pathways; benfotiamin

Striking increase in the incidence of infective endocarditis associated with recreational drug abuse in urban South Africa

Background. We have recently noted a dramatic rise in the number of patients with infective endocarditis (IE) related to intravenous (IV) nyaope (a mixture of heroin, cocaine and antiretroviral drugs) presenting to Chris Hani Baragwanath Academic Hospital in Johannesburg, South Africa.Objectives. To document the clinical and echocardiographic characteristics of these patients.Methods. Clinical and echocardiographic characteristics of all patients (N=68) with IE due to IV nyaope use were retrospectively extracted from hospital records (December 2014 - February 2017).Results. The mean (standard deviation) age of the patients was 25.8 (4.5) years (97.1% were male). Withdrawal symptoms were noted in 25.1% of cases, fever in 58.8%, dyspnoea in 86.7% and right ventricular failure in 42.6%. Most patients were HIV-positive (76.1%), with CD4+ cell counts of &lt;200 cells/µL in 8.8% of the total, 58.1% had hepatitis C infection, and only three were on antiretrovirals. Septic pulmonary emboli were noted in 61.8%. Blood cultures revealed Staphylococcus aureus in 61.2%, Enterococcus faecalis in 8.8% and Pseudomonas aeruginosa in 1 patient; 29.2% had sterile cultures and 8.8% polymicrobial infection. Severe right ventricular systolic dysfunction (RVS' Doppler velocity &lt;10 cm/s) and pulmonary hypertension were noted in 19.1% and 62.2% of patients, respectively. Pericardial effusion was noted in 37.8%. The most commonly involved valve was the tricuspid (60.1%), followed by the mitral (17.2%), aortic (2.9%) and pulmonary (1 patient) valves. Combined valve lesions were noted in 19.1% of patients. Ten patients (14.7%) died. The main predictor of in-hospital mortality was S. aureus infection (odds ratio 5.0; p=0.042).Conclusions. We have documented the common clinical and echocardiographic characteristics of patients with IE secondary to IV nyaope use. IE due to IV drug use is responsible for considerable morbidity and mortality in a predominantly young male population. Â

Pasteur\u27s legacy featured at UM shows, lecture

AIMS: Left atrial (LA) volume is an important predictor of morbidity and mortality in cardiovascular disease. Left atrial strain is a feasible technique for assessing LA function. The EchoNoRMAL study recently highlighted the possibility that ethnic-based differences may exist in LA size. There is a paucity of data regarding LA parameters in an African population. We sought to establish normative values for LA volumetric and strain parameters in a black population. METHODS AND RESULTS: This cross-sectional study comprised 120 individuals between 18 and 70 years of age. Left atrial volumes were measured by biplane Simpson\u27s method, and strain parameters were measured using Philips QLAB 9 (Amsterdam, The Netherlands) speckle-tracking software. The mean age was 38.7 ± 12.8 years (50% male). Maximum LA volume indexed (LAVi), pre-atrial LAVi, and minimum LAVi were 19.7 ± 5.9, 12.2 ± 4.4, and 7.7 ± 3.2 mL/m(2), respectively. Females had a higher LAVi compared with males (20.9 ± 6.3 vs. 18.6 ± 5.3 mL/m(2), P = 0.04). Peak global longitudinal strain in the reservoir phase (ɛR) was 39.0 ± 8.3%, and the peak LA strain in the contractile phase (ɛCT) was -2.7 ± 2.5%. No gender differences were noted in ɛR. Body surface area, age, and weight were the main determinants of ɛR on multivariate linear regression analysis. CONCLUSION: The data reported in this study establish the normal reference values for phasic LA volumes and strain in a normal black population and serve as a platform for future studies

Relationships between plasma amino acid concentrations and blood pressure in South Africans of African descent

Oral supplementation with the amino acid arginine, the precursor of the vasodilator nitric oxide (NO), is associated with a reduction in blood pressure (BP). However, it is uncertain whether a decreased plasma arginine concentration predicts increases in BP. We assessed the relationship between fasting plasma arginine or other amino acid concentrations and 24 hour ambulatory BP in 75 nevertreated participants recruited from the Johannesburg area, 55 of whom were male. Plasma amino acid concentrations were measured with high performance liquid chromatography-mass-spectrometry. Plasma arginine concentrations were not inversely correlated with ambulatory BP. However, plasma arginine concentrations were increased in 36 participants with a mean daytime systolic BP &gt;140 mm Hg (61 ± 17 μmol/L) as compared to the remaining participants (54 ± 15 μmol/L, p‹0.05). Moreover, plasma arginine concentrations were positively correlated with 24-hour diastolic BP (r=0.26, p‹0.05). In males with a BMI‹30kg/m2, plasma arginine concentrations were positively correlated with both night diastolic (r=0.46, p‹0.005) and systolic (r=0.42, p‹0.005) BP. In a multivariate model with adjustments for age gender, body mass index, and other amino acid concentrations, plasma arginine concentrations were independently and positively associated with night diastolic BP (p‹0.05). In conclusion plasma arginine concentrations are positively associated with ambulatory BP in a group of participants of African descent in South Africa. These data do not support the notion that deficiencies of arginine, the amino acid substrate for NO, are related to increases in BP in groups of African ancestry living in South Africa. However, as with other ethnic groups, the positive relationship between plasma arginine concentrations and BP suggests a reduced capacity to utilise the amino acid substrate for NO synthesis

Impact of initiating carvedilol before angiotensin-converting enzyme inhibitor therapy on cardiac function in newly diagnosed heart failure

ObjectivesThe purpose of this research was to evaluate the therapeutic value of initiating a beta-blocker before an angiotensin-converting enzyme inhibitor (ACEI) in the treatment of heart failure.BackgroundAlthough ACEI and carvedilol produce benefits in heart failure, whether the order of initiation of therapy determines the impact on left ventricular (LV) function and New York Heart Association functional class (NYHA FC) has not been determined.MethodsA single-center, prospective, randomized, open-label study was performed. We evaluated whether initiation of therapy with carvedilol either before (n = 38) or after (n = 40) perindopril therapy in newly diagnosed patients in NYHA FC II to III heart failure with idiopathic dilated cardiomyopathy, with the addition of the alternative agent after six months, determined subsequent changes in NYHA FC and LV function (echocardiography and radionuclide ventriculography). Study drugs were titrated to maximum tolerable doses.ResultsThere were no differences in baseline characteristics between the study groups. After 12 months 11 patients died (6 in the group where the ACEI was initiated). At 12 months the group receiving carvedilol as initial therapy achieved a higher tolerable dose of carvedilol (43 ± 17 mg vs. 33 ± 18 mg, p = 0.03); a lower dose of furosemide (p &lt; 0.05); and better improvements in symptoms (NYHA FC, p &lt; 0.002), LV ejection fraction (radionuclide: 15 ± 16% vs. 6 ± 13%, p &lt; 0.05; echocardiographic, p &lt; 0.01), and plasma N-terminal pro-brain natriuretic peptide concentrations (p &lt; 0.02).ConclusionsAs opposed to the conventional sequence of drug use in the treatment of heart failure, initiation of therapy with carvedilol before an ACEI results in higher tolerable doses of carvedilol and better improvements in FC and LV function

Engaging 100% of Malawi’s human development potential for sustainable socio-economic development

Gender inequality in Malawi is associated with deep-rooted inequitable laws, norms, and practices, hampering women and girls' access to opportunities, resources, and power. Unequal gender roles and unequal power relations between men and women persist across all social institutions, giving rise to multiple forms of discrimination against women, illustrated in the country's poor performance on various gender-disaggregated socio-economic development indices (Table 1). Strengthening Gender and Inclusivity in STI highlights the contextual factors driving gender and inclusivity disparities in science, technology and innovation (STI) in Malawi and options and strategies for addressing disparity gaps in some of UNESCO’s STEM and Gender Advancement (SAGA) policy impact areas

Engaging 100% of Botswana’s human development potential for sustainable socioeconomic development

Strengthening Gender and Inclusivity in Science, Technology and Innovation (STI) highlights factors driving gender and inclusivity disparities in Botswana, along with options and strategies for addressing disparity gaps: social norms and stereotypes; education (primary, secondary and tertiary); the career progression environment; research content and practice; policy; and entrepreneurship and innovation. Gender disparities in Botswana are mainly due to reproductive health, empowerment, culture, and the labour market that hinders women and girls' access to opportunities, resources, and power. The Abolition of the Marital Power Act 2004 provides for equal rights and status of women and men in marriage. The country profile measures challenges and progress using various statistical indicators