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

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

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The credo - reaffirming our professionalismThe quest for ethics in medicineThe public service labour relations shamblesSensitisation, pre-emptive and total analgesiaThe resurrection ofprimary percutaneous transluminal coronary angioplasty for the treatment of acute myocardial infarctionPrimary health care depends on the district health syste

Antiphospholipid antibodies in black south africans with hiv and acute coronary syndromes: prevalence and clinical correlates

<p>Abstract</p> <p>Background</p> <p>HIV infection is associated with a high prevalence of antiphospholipid antibodies (aPL) and increased thrombotic events but the aetiopathogenic link between the two is unclear.</p> <p>Findings</p> <p>Prospective single centre study from Soweto, South Africa, comparing the prevalence of aPL in highly active anti-retroviral therapy (HAART) naïve HIV positive and negative patients presenting with Acute Coronary Syndromes (ACS). Between March 2004 and February 2008, 30 consecutive black South African HIV patients with ACS were compared to 30 black HIV negative patients with ACS. The HIV patients were younger (43 ± 7 vs. 54 ± 13, p = 0.004) and besides smoking (73% vs. 33%, p = 0.002) and lower HDL levels (0.8 ± 0.3 vs. 1.1 ± 0.4, p = 0.001) had fewer risk factors than the control group. HIV patients had a higher prevalence of anticardiolipin (aCL) IgG (47% vs. 10%, p = 0.003) and anti-prothrombin (aPT) IgG antibodies (87% vs. 21%, p < 0.001) but there was no difference in the prevalence of the antiphospholipid syndrome (44% vs. 24%, p = N/S) and aPL were not predictive of clinical or angiographic outcomes.</p> <p>Conclusions</p> <p>Treatment naïve black South African HIV patients with ACS are younger with fewer traditional coronary risk factors than HIV negative patients but have a higher prevalence and different expression of aPL which is likely to be an epiphenomenon of the HIV infection rather than causally linked to thrombosis and the pathogenesis of ACS.</p