Echocardiographic left atrial remodelling and determinants of left atrial size in the early phase of high blood pressure: a comparative cross-sectional study in Douala, Cameroon.

BACKGROUND: Left atrial remodelling (LAR) has been described in Western populations with chronic hypertension and is associated with a higher risk of adverse cardiovascular events. Although hypertension tends to occur earlier and is more severe in sub-Saharan Africa than in more developed nations, LAR and its associated factors in these African hypertensive subjects have been poorly elucidated. OBJECTIVES: To assess left atrial structural remodelling in black hypertensive patients and determine factors associated with left atrial size. METHODS: This was a cross-sectional, comparative study carried out in two tertiary hospitals in Douala, Cameroon over a period of three months. Fifty-two patients, either newly diagnosed with hypertension or known hypertensives treated for less than a year, were consecutively recruited. These patients were matched (unpaired matching) for age and gender to 40 randomly selected healthy subjects. The posterior-anterior diameter indexed to body surface area (BSA), volume indexed to BSA, and longitudinal and transverse diameters of the left atrium (LA) were measured using transthoracic echocardiography, in accordance with the American Society of Echocardiography guidelines. LAR was defined as increase in LA size, characterised by LA volume ≥ 34 ml/m2. Early morning urine was analysed for microalbuminuria using urine strips to obtain spot albumin/creatinine ratio. Data were analysed using SPSS version 23 and statistical significance was set at p < 0.05. RESULTS: The gender distribution and mean age were similar between the two groups. Hypertensive patients had significantly higher mean body mass index, left ventricular mass and an altered diastolic function. They also had significantly higher LA longitudinal diameter (50.0 vs 47.4 mm; p = 0.045), surface area (17.9 vs 15.5 cm2; p = 0.003) and volume (52.4 vs 43.8 ml; p = 0.002) compared to the non-hypertensive counterparts. Fourteen patients (26.9%) had LA enlargement compared to one (2.5%) in the non-hypertensive group (odds ratio = 9.78, CI: 2.67-35.8, p < 0.0001). Diastolic dysfunction (p = 0.008) was the only independent predictor of LA size in the hypertensive subjects. Microalbuminuria did not significantly correlate with LA size. CONCLUSIONS: Our study shows evidence of LAR in newly diagnosed black African patients with hypertension, characterised by an increase in the LA length, surface area and volume. Future studies are warranted to better elucidate the biological mechanisms underlying the link between the early phase of hypertension and LAR, as well as its prognostic implications in our population.

Correlations of left ventricular systolic function indices with aortic root systolic excursion (ARSE): A cross-sectional echocardiographic study.

BACKGROUND: Heart failure (HF), is a major public health issue globally. Echocardiography is cost-effective in the diagnosis in expert hands. This study was conducted to estimate the usefulness of Aortic Root Systolic Excursion (ARSE) as a simple and accurate measure to estimate Left Ventricular (LV) function. METHODS: This was a cross-sectional echocardiographic study among adults aged ≥ 18 years, with or without heart failure, in sinus rhythm, and with no LV out-let obstruction. We studied the correlations of ARSE with some selected indices of LV Systolic Functions. We determined optimal cut-offs of ARSE in detecting LV dysfunction. We generated a simple regression equation to best estimate LV ejection fraction according to the modified Simpson method. RESULTS: Overall 213 echocardiograms were included from 106 males (49.8%), with mean age of the participants being 52.4 (SD: 18.3) years. The rate of LV systolic dysfunction was highest with Teicholz method (17.4%) and lowest with MAPSE method (5.2%). ARSE correlated with the LV functions. This was highest for the Simpson method (r = 0.619, p<0.001), and lowest for the ITV method (r = 0.319, p<0.001). Optimal cut-offs to detect LV systolic dysfunction was ≈ 6.6 mm. For an LV ejection fraction < 55%, the sensitivity was 82.9%, and the specificity was 97.2%, with an AUROC of 91.6%.The logarithmic regression equation was best in predicting LV ejection fraction (AUC: 60.2%), followed by the power model (AUC: 56.7%), and the linear model (AUC: 53.6%). CONCLUSION: ARSE correlated well with LV systolic function. The cut-off ≤ 6.5 mm suggest LV systolic dysfunction. LV Ejection Fraction was best estimated with the generic equation: LVEF (%) = 29 x In [ARSE].

Effect of propranolol on heart rate variability in hyperthyroidism.

OBJECTIVES: We aimed to determine the effect of propanolol on heart rate variability (HRV) in hyperthyroidism before antithyroid treatment. This was a before and after study, on ten patients presenting overt hyperthyroidism naïve to treatment. In each patient, a resting electrocardiogram was done followed by estimation of cardiac autonomic dysfunction during five maneuvers (Ewing battery tests). Long term HRV measurement was done using 24 h ambulatory electrocardiographic recording. This automatically provided estimation of HRV using SDNN and RMSSD index, LF, HF, and HF/LF ratio. After baseline investigations, 40 mg of propanolol was given twice a day for 3 days and same parameters were measured after 72 h of treatment. RESULTS: Our patients were aged 40 ± 10 years. Propanolol significantly reduced RR and HR interval (669 ms vs 763 ms and 91 vs 79 bpm; p < 0.01). QT and PR space were significantly extended (360 vs 384 ms and 133 vs 172 ms; p = 0.01). It increases QRS complex and blood pressure response to sustained handgrip but failed to modify previously decreased heart response to deep breathing. HRV parameters such as SDNN, RMSSD, LF, HF and sympathovagal balance estimate by HF/LF ratio remained unchanged. Although a significant reduction in heart excitability, propanolol failed to restore a good sympathovagal balance in hyperthyroidism. Trial registration NCT03393728 "Retrospectively registered".

Prevalence and correlates of chronic kidney disease in a group of patients with hypertension in the Savanah zone of Cameroon: a cross-sectional study in Sub-Saharan Africa.

BACKGROUND: The prevalence of chronic kidney disease (CKD) is increasing worldwide due to an increase in the risk factors such as hypertension. The greatest burden is in low-income settings, coupled with late diagnosis and limited management resources. This work aimed at studying the prevalence and risk factors of CKD in a group of patients with hypertension in the Savanah zone in Sub-Saharan Africa (SSA). METHODS: We carried out a cross-sectional study between January and May 2016 in the regional Hospital of Garoua-Cameroon. Participants were adults ≥18 years of both sexes, who had a diagnosis of hypertension. Patients underwent a comprehensive clinical, biological, and electrocardiographic evaluation. RESULTS: A total of 400 patients with hypertension were included, of whom 132 (33%; 95% CI: 28.6-37.8%) were males. Their mean age was 54.16±11.17 years. Hypertension was controlled in 122 (30.5%; 95% CI: 26.2-35.2%) participants. Twelve percent had a positive urine dipstick for proteins. The mean glomerular filtration rate (GFR) was 75.27±24.87 mL/min/1.73m2. The prevalence of CKD was seen in 129 (32.3%; 95% CI: 27.9-36.98) participants. Stage 3A was the most frequent (62.01%). The main comorbidities were anemia (44.5%), obesity (39.75%), diabetes (32%), consumption of traditional medicines (15.75%), and hyperuricemia (10.75%). After multivariate analysis, age >50 years (aOR: 1.75; 95% CI: 1.06-2.89; P=0.027), female sex (aOR: 2.21; 95% CI: 1.29-3.78; P=0.0035), obesity (aOR: 1.58, 95% CI: 1.01-2.44; P=0.026) and the hyperuricemia (aOR: 3.67; 95% CI: 1.78-7.58; P<0.001) were independently associated with CKD. CONCLUSIONS: The prevalence of CKD in adults with hypertension was high. This was associated with age greater than 50 years, female sex, obesity and the hyperuricemia.

Echocardiographic and electrocardiographic abnormalities in adults living with human immunodeficiency virus: a cross-sectional study in the Yaoundé Central Hospital, Cameroon.

BACKGROUND: Cardiac involvement is frequent in the course of human immunodeficiency virus (HIV) infection disease. This work aimed at studying the profile of echocardiographic and electrocardiography (ECG) abnormalities in adults living with HIV (PLHIV), compared to those not infected with HIV at the treatment unit of the Yaoundé Central Hospital. METHODS: We carried out a case-control study over three months at the HIV treatment unit. We included adults of both sexes, aged ≥21 years, HIV-infected (cases), and age and sex matched controls. Those with a history of heart disease were excluded. We collected sociodemographic, clinical, ECG, and echocardiographic data. RESULTS: We included 59 PLHIV and 59 age-sex matched controls without HIV infection. The prevalence of echocardiographic abnormalities was 28.8% in cases, and 8.5% in the control group (P=0.005). The prevalence of ECG abnormalities was 28.8% in the cases, and 18.6% in the control group (P=0.195). The main echocardiographic abnormalities (cases versus controls) were aortic regurgitation (10.2% versus 3.4%, P=0.144), right atrial dilation (6.8% versus 1.7%, P=0.178), diastolic dysfunction (5.1% versus 1.7%, P=0.310), and Left ventricular hypertrophy (5.1% versus 0%, P=0.080). The main ECG abnormalities (cases versus controls) were abnormal repolarization (11.9% versus 5.1%, P=0.187), sinus tachycardia (10.2% versus 6.8%, P=0.510), and atrial fibrillation (5.1% versus 0%, P=0.080). HIV infection was significantly associated with echocardiographic abnormalities and not with ECG abnormalities. The degree of immune deficiency was independently associated with the occurrence of echocardiographic and ECG abnormalities. CONCLUSIONS: HIV infected adults have more echocardiographic and ECG abnormalities compared to non-infected adults. The ECG and echocardiographic anomalies varied, and depends on the severity of immune deficiency.