Publications by authors named "Ferande Peters"

• RHD is a rare cause of severe valvular AS. • Rheumatic MS typically accompanies rheumatic AV disease. • 2D and 3D echocardiography are essential in the assessment of rheumatic AS.

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Background: Whether differential effects of volume load on left ventricular mass (LVM) and function occur in sustained volume-dependent primary hypertension, and the impact of atrial natriuretic peptide (ANP) on these effects, is unknown.

Methods: From aortic pressure, velocity and diameter measurements and echocardiography, we determined in an African community ( = 772), the impact of systemic flow-induced increases in central pulse pressure (PPc) and circulating ANP (ELISA) on LVM and indexes of function.

Results: Stroke volume (SV), but not aortic flow (Q), was associated with LVM and mean wall thickness (MWT) beyond stroke work and confounders ( < 0.

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Introduction: Circulating uric acid, ferritin, albumin, intact parathyroid hormone and gamma-glutamyl transferase each participate in biochemical reactions that reduce or/and enhance oxidative stress, which is considered the final common pathway through which pathophysiological mechanisms cause uremic cardiomyopathy. We hypothesized that the respective biomarkers may be involved in the development of uremic cardiomyopathy characteristics and can be useful in their identification among chronic kidney disease patients.

Methods: We assessed traditional and non-traditional cardiovascular risk factors including biomarker concentrations and determined central systolic blood pressure using SphygmoCor software and cardiac structure and function by echocardiography in 109 (64 non-dialysis and 45 dialysis) patients.

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Aims: A lower heart rate (HR) increases central blood pressure through enhanced backward wave pressures (Pb). We aimed to determine whether these relationships are modified by increases in aortic stiffness.

Methods: Using non-invasive central pressure, aortic velocity and diameter measurements in the outflow tract (echocardiography), we assessed the impact of aortic stiffness on relationships between HR and arterial wave morphology in 603 community participants < 60 years of age, 221 ≥ 60 years, and in 287 participants with arterial events [stroke and critical limb ischemia (CLI)].

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Background: Whether systolic blood pressure (SBP) control in sustained volume-dependent primary hypertension is associated with blunted ANP (atrial natriuretic peptide) relationships with indexes of volume load is unknown.

Methods: Systemic hemodynamics (central pressure, echocardiographic aortic velocity and diameter measurements in the outflow tract), circulating ANP concentrations (ELISA assays) and glomerular and tubular function (24-hour urine collections [n=519]) were determined in a community of African ancestry (n=772).

Results: As compared with those with a controlled SBP, those with an uncontrolled SBP (n=198) showed lower ANP concentrations (<0.

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Background: A lower heart rate (HR) increases left ventricular (LV) ejection volume. Whether this contributes to the adverse effects of HR on central pulse pressure (PPc) through reservoir volume effects is uncertain.

Methods: Using noninvasive central pressure, aortic velocity, and diameter measurements in the outflow tract (echocardiography), we assessed the role of LV ejection volume as a determinant of HR relations with PPc in 824 community participants.

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Purpose: We assessed whether aortic stiffness and pulsatile pressures can mediate chronic kidney disease (CKD)-associated impaired diastolic function.

Participants And Methods: In 276 black Africans including 46 CKD (19 non-dialysis; 27 dialysis) and 230 control subjects, pulse wave velocity (PWV) estimated aortic stiffness and pulsatile pressures (forward and backward wave pressure, central systolic blood pressure (CSBP) and pulse pressure (CPP)) were determined by applanation tonometry; e' as an index of left ventricular active relaxation and E/e' as a measure of left ventricular filling pressure or passive relaxation were evaluated by echocardiography.

Results: In age, sex, traditional cardiovascular risk factor and mean arterial pressure (MAP) adjusted regression models, CKD was inversely associated with e' (p = 0.

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Aims: Although peak aortic flow (Q) is now recognized as a major determinant of hypertension in Africa, current therapy has no proven ability to target this change. The mechanisms of this effect, therefore, require elucidation. We compared the intrafamilial aggregation and heritability of Q to that of the vascular determinants of pulse pressure (PP) and SBP in Africa.

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Through both backward (Pb) and forward (Pf) wave effects, a lower heart rate (HR) associates with increased central (PPc), beyond brachial pulse pressure (PP). However, the relative contribution to Pf of aortic flow (Q) versus re-reflection of Pb, has not been determined. Using central pressure, aortic velocity and diameter measurements in the outflow tract (echocardiography), we constructed central pressure waveforms that account for the relative contribution of Q versus re-reflection to Pf.

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Background: Sub-Saharan Africa is undergoing an epidemiological transition fueled by the interaction between infectious and cardiovascular diseases. Our cross-sectional study aimed to characterize the spectrum of abnormalities suggesting end-organ damage on ECG and transthoracic echocardiograms (TTE) among older adults with cardiovascular diseases in rural South Africa.

Methods: The prevalence of ECG and TTE abnormalities was estimated; χ analyses and multivariable logistic regressions were performed to test their association with sex, hypertension, and other selected comorbidities.

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Aims: Whether renal mechanisms of hypertension primarily translate into increases in systemic vascular resistance (SVR) in all populations is uncertain. We determined whether renal mechanisms associate with either increases in SVR (and impedance to flow) or systemic flow in a community of African ancestry.

Method: In a South African community sampled across the full adult age range (n = 546), we assessed stroke volume (SV), peak aortic flow (Q), SVR, characteristic impedance (Zc) and total arterial compliance (TAC) from velocity and diameter measurements in the outflow tract (echocardiography) and central arterial pressures.

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Background: Whether in volume-dependent primary hypertension, concentric left ventricular (LV) remodeling beyond hypertrophy (LVH) represents the impact of a pressure rather than a volume overload, is unclear.

Methods: Using central arterial pressure, and aortic velocity and diameter measurements in the outflow tract (echocardiography), we determined the factors that associate with concentric LVH or remodeling in a community of African ancestry (n = 709) with prevalent volume-dependent primary hypertension.

Results: Both left ventricular mass index (LVMI) and relative wall thickness (RWT) were positively and independently associated with end diastolic volume (EDV), stroke volume (SV), and peak aortic flow (Q) (P < 0.

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Introduction: We hypothesized that post transplantation anaemia and persistent secondary hyperparathyroidism are potential determinants of diastolic function in stable kidney transplant recipients.

Methods: We assessed traditional and non-traditional cardiovascular risk factors and determined carotid artery intima-media thickness and plaque by ultrasound, arterial function by applanation tonometry using SphygmoCor software and diastolic function by echocardiography in 43 kidney transplant recipients with a transplant duration of ≥6 months, no acute rejection and a glomerular filtration rate of ≥15 mL/min/1.73m.

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Aims: To determine whether the confounding influence of stroke work on left ventricular mass (LVM) limits the ability of LVM to detect hypertensive LV dysfunction in systemic flow-dependent hypertension.

Methods: In a community with prevalent systemic flow-dependent hypertension (n = 709), arterial haemodynamics, LVM and LV function were determined using central arterial pressure, aortic velocity and diameter measurements in the outflow tract, and echocardiography with tissue Doppler imaging.

Results: In multivariate models, stroke work showed markedly stronger relations with LVM index (LVMI) than blood pressure load [central arterial SBP (SBPc), backward wave pressure (Pb), 24-h SBP] (P < 0.

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Article Synopsis
  • The study aimed to explore how aortic stiffness affects atherosclerosis and small vessel damage, focusing on whether this influence is linked to increased central arterial pressures from resistance to blood flow.
  • Involving 1021 participants, researchers measured central arterial health using methods like SphygmoCor for pressure and echocardiography for flow and diameter, finding key relationships among stiffness measures, blood flow, and indicators of organ health.
  • The results indicated that both characteristic impedance (Zc) and pulse wave velocity (PWV) are independently related to health markers like carotid thickness and kidney function, underlining that the effects of aortic stiffness on vascular damage extend beyond just traditional blood pressure metrics.*
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Aims: Age-related increases in systemic blood flow [stroke volume (SV), cardiac output (CO), and aortic flow (Q)] contribute substantially to untreated or inadequately controlled (uncontrolled) blood pressure (BP) in Africa. We aimed to identify the haemodynamic determinants of uncontrolled systolic--diastolic (Syst--diast HT) versus uncontrolled isolated systolic (ISH) or diastolic (IDH) hypertension.

Methods: Using central arterial pressure and aortic outflow tract velocity and diameter measurements (echocardiography), the haemodynamic correlates of BP were determined in 725 community participants of African ancestry (19.

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Background: Several large, prospective screening studies of predominantly Caucasian patients have suggested that hypertrabeculation may not necessarily be pathologic unless there is concomitant left ventricular (LV) dysfunction, LV dilatation, history of arrhythmia, family history, or characteristic gene mutations. This conundrum may be magnified in blacks, in whom hypertrabeculation and LV hypertrophy is more common. We therefore investigated the frequency of hypertrabeculation/isolated LV noncompaction (ILVNC) phenotype in normal black Africans and evaluated LV function using sensitive measures of deformation and twist.

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Although hypertension in groups of African ancestry is volume-dependent, the relative impact of systemic flow (stroke volume, peak aortic flow [Q]) versus vascular mechanisms (systemic vascular resistance, aortic characteristic impedance [Zc], total arterial compliance) components of arterial load has not been evaluated across the adult age range. In participants of African ancestry (n=824, age=16-99 years, 68.3% female), using central arterial pressure and aortic velocity and diameter measurements in the outflow tract, we determined the hemodynamic correlates of age-related increases in blood pressure.

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Background: Chronic mitral regurgitation (MR) historically has been shown to primarily affect left ventricular (LV) function. The impact of increased left atrial (LA) volume in MR on morbidity and mortality has been highlighted recently, yet the LA does not feature as prominently in the current guidelines as the LV. Thus, we aimed to study LA and LV function in chronic rheumatic MR using traditional volumetric parameters and strain imaging.

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Rheumatic heart disease (RHD) is the only preventable cardiovascular disease which causes significant morbidity and mortality particularly in low- and middle-income countries. Early clinical diagnosis is key, the updated Jones criteria increases the likelihood of diagnosis in endemic settings, including the echo diagnosis of sub-clinical carditis, polyarthralgia and monoarthritis as well as amended thresholds of minor criteria. The mainstay of rheumatic heart valve disease (RHVD) is a thorough clinical and echocardiographic investigation while severe disease is managed with medical, interventional and surgical treatment.

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Objective: The age at which arteriosclerosis begins to contribute to events is uncertain. We determined, across the adult lifespan, the extent to which arteriosclerosis-related changes in arterial function occur in those with precipitous arterial events (stroke and critical limb ischemia). Approaches and Results: In 1082 black South Africans (356 with either critical limb ischemia [n=238] or stroke [n=118; 35.

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The relative contribution of loading conditions at different ages across the full adult lifespan to decreases in left ventricular (LV) diastolic function is unclear. Using central arterial pressure and aortic velocity and diameter measurements in the outflow tract, we determined the contribution of systemic vascular resistance, compression wave pressures (characteristic impedance [Zc]×aortic flow [Q], [P]) and backward wave pressures (Pb) to LV diastolic function (echocardiography) in a community sample across the full adult lifespan (n=605). Starting from early adulthood, stepwise age-related increases in LV filling pressures (E/e') and decreases in myocardial relaxation (e') were noted (<0.

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Background: Isolated left ventricular non-compaction (ILVNC), dilated cardiomyopathy (DCMO) and hypertrophic cardiomyopathy (HCM) are diseases that may be present in family members of patients with ILVNC. The primary aim of this study was to identify the prevalence and spectrum of cardiomyopathy in first-degree relatives of patients with ILVNC. A secondary aim was to compare a strategy of clinical screening, utilising only a clinical assessment and electrocardiogram (ECG), compared to one that included echocardiography for screening of family members of patients with ILVNC.

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Background: It is unknown whether ethnic differences occur with regard to right heart echocardiographic parameters. The aim of this study therefore was to establish normative values of left and right heart parameters in a black African population and to evaluate the effect of age and body mass index (BMI) on specific right ventricle (RV) parameters.

Methods: Two hundred fifty-three normal subjects were prospectively studied.

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Aims: Right ventricular (RV) systolic function is an important predictor of mortality but has been poorly studied in chronic rheumatic mitral regurgitation (CRMR). We studied RV systolic function using speckle-tracking echocardiography (STE) in patients with CRMR.

Methods: Seventy-seven patients with CRMR and 40 healthy controls were enrolled in a cross-sectional study at Chris Hani Baragwanath Hospital between January and October 2014.

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