Influence of cigarette smoking on the Index of Cardiac Electrophysiological Balance in apparently healthy Angolans.

Background: Tobacco use accelerates atherosclerosis and is one of the predictors of death from ischemic heart disease, arrhythmias, heart failure, and sudden death. A new non-invasive parameter, the Index of Cardiac Electrophysiological Balance (iCEB) between depolarization and repolarization of the action potential, was considered a new biomarker for the identification of patients at increased arrhythmic risk. Objectives: We aimed to evaluate the iCEB in apparently healthy Angolans with habitual cigarette smoking compared to non-smokers. Subjects and methods: Data were obtained from the CardioBengo study, a cross-sectional community-based study in which a random sample of individuals aged between 15 and 84 years was selected. In total, 214 apparently healthy subjects, 102 smokers, and 112 non-smokers in the same age group were included in the final analysis. Results: The average age of the participants was 42.17 ± 13.04 years old and 26.6% of the sample was female. Smoking subjects had higher iCEB and corrected Index of Cardiac Electrophysiological Balance (iCEBc) values compared with non-smoking controls (4.39 vs. 4.25; p = 0.024, respectively), and (4.74 vs. 4.57; p = 0.030, respectively). Conclusions: In summary, iCEB and iCEBc were significantly higher in habitual smokers than in nonsmokers, which represents an increased risk of ventricular arrhythmogenesis in healthy habitual smokers. To the best of our knowledge, this is the first study performed in Africa to evaluate iCEB in smokers, making this type of study very important in low- and middle-income countries in the context of epidemiological transition.

Electrocardiographic findings in pregnant women in Angola.

BACKGROUND: Studies on the electrocardiogram findings in African pregnant women are limited. There is no information available in the literature on the electrocardiographic parameters of pregnant Angolan women. OBJECTIVES: The aim of this study was to describe electrocardiographic findings in women with normal pregnancies in Bengo Province, Angola. METHODS: This is a community-based study with a cross-sectional design conducted between September 2013 and March 2014 in Bengo. The study involved 114 black pregnant women, compared with a paired control group comprising of 120 black non-pregnant women, aged 15 to 42 years. A 12-lead electrocardiogram and a rhythm strip were recorded for all participants. RESULTS: In this study, the mean age was 26.2 ± 7.3 years. Comparing pregnant women vs. non-pregnant, we found the following mean values: Heart rate (83 bpm vs. 74 bpm, p < .001), PR interval (146 ms vs. 151 ms, p = .034), QT interval (360 ms vs. 378 ms, p < .001), QTIc Fridericia (398 ms vs. 403, p = .017), QTIc Framingham (399 ms vs. 404 ms, p = .013) and T-wave axis (340 vs. 410 , p = .001).The main electrocardiographic changes found were: Sinus tachycardia (4.4% vs. 2.5%), T-wave inversion (14.9% vs. 1.7%), Minor ST segment depression (4.5% vs. 0%) and left ventricular hypertrophy (11.4% vs. 11.7%, p = .726). CONCLUSIONS: Pregnant Angolan women compared with controls, had several significantly higher values for heart rate, and significantly lower values of systolic blood pressure and diastolic blood pressure, PR interval, QT interval, QTc interval by Fridericia and Framingham and T-wave axis. Sinus tachycardia, T-wave inversion, and left ventricular hypertrophy, were the main electrocardiographic changes found.

Prevalence of major and minor electrocardiographic abnormalities and their relationship with cardiovascular risk factors in Angolans.

AIMS: To identify the prevalence of major and minor electrocardiographic abnormalities and their association with the main risk factors for cardiovascular disease in a population in the province of Bengo, northern Angola. METHODS: A cross-sectional community-based study was conducted and a representative random sample stratified by sex and age was selected. In total, 2379 black individuals were included in the final analysis. A standard 12-lead ECG were recorded from all participants, analyzed and processed by the University of Glasgow software and coding by the Minnesota code. RESULTS: 22.3% of participants had minor electrocardiographic abnormalities and 4.58% major ECG abnormalities. The most common minor ECG abnormalities were abnormal T wave inversion, minor isolated ST abnormalities and premature beats. The most common major ECG abnormalities were Left ventricular hypertrophy with major ST-T abnormalities, Ventricular conduction defects and major Q-wave abnormalities. Hypertension, diabetes mellitus, hypercholesterolemia, alcohol consumption and smoking, were significantly associated with major and minor electrocardiographic abnormalities. CONCLUSIONS: In this study several participants had minor and major electrocardiographic abnormalities. Minor electrocardiographic abnormalities were more prevalent in men and major abnormalities in women. The electrocardiographic abnormalities had significant associations with the main cardiovascular risk factors.

Normal limits of the electrocardiogram in Angolans.

INTRODUCTION: Studies on the normal electrocardiogram limits in African populations are limited, especially in sub-Saharan Africa. There is no literature describing normal ECG limits in Angolans. OBJECTIVES: The aim of this study is to establish the normal ECG limits for adult Angolans, without established heart disease, stratified by gender and age. METHODS: A cross-sectional study was performed, involving 2179 participants from a population in northern Angola, without established heart disease, aged between 15 and 74 years. A 12­lead ECG and a rhythm strip were recorded for all participants and analysed and processed by the University of Glasgow software and encoded by the Minnesota Code. The normal range of the electrocardiographic parameters were established as the 2nd and 98th percentiles of the measurement distribution per age group and gender. Mann-Whitney and Kruskal-Wallis tests were used for two independent groups and Bonferroni adjustments were used for multiple testing. GAMLSS models were used to obtain the continuous age-dependent percentile curves. RESULTS: The normal range of the ECG differed between men and women: heart rate 49 to 100 bpm vs. 55 to 108 bpm, P wave duration 81 to 130 ms vs. 84 to 130 ms, PR interval 119 to 210 ms vs. 120 to 202 ms, QRS duration 74 to 110 ms vs. 70 to 104 ms, QT interval 324 to 441 ms vs. 314 and 438 ms, P-wave axis - 29 to 850 vs. -18 to 810, QRS-wave axis - 13 to 850 vs. -180 and 820, T-wave axis 0 to 720 vs. -8 to 730, Sokolow-Lyon index 2.13 to 6.21 mV vs. 1.60 to 4.87 mV, Cornell index 0.17 to 6.24 mV vs. 0.14 mV to 4.35 mV. CONCLUSIONS: The values described for the electrocardiographic measurements above can act as a reference framework for Angolan adults without established heart disease. Our study suggests that the normal range of most ECG parameters vary according to age and sex and the ECG diagnostic criteria must therefore be specific for these demographic measures.

Role of malnutrition and parasite infections in the spatial variation in children's anaemia risk in northern Angola.

Anaemia is known to have an impact on child development and mortality and is a severe public health problem in most countries in sub-Saharan Africa. We investigated the consistency between ecological and individual-level approaches to anaemia mapping by building spatial anaemia models for children aged ≤15 years using different modelling approaches. We aimed to (i) quantify the role of malnutrition, malaria, Schistosoma haematobium and soil-transmitted helminths (STHs) in anaemia endemicity; and (ii) develop a high resolution predictive risk map of anaemia for the municipality of Dande in northern Angola. We used parasitological survey data for children aged ≤15 years to build Bayesian geostatistical models of malaria (PfPR≤15), S. haematobium, Ascaris lumbricoides and Trichuris trichiura and predict small-scale spatial variations in these infections. Malnutrition, PfPR≤15, and S. haematobium infections were significantly associated with anaemia risk. An estimated 12.5%, 15.6% and 9.8% of anaemia cases could be averted by treating malnutrition, malaria and S. haematobium, respectively. Spatial clusters of high risk of anaemia (>86%) were identified. Using an individual-level approach to anaemia mapping at a small spatial scale, we found that anaemia in children aged ≤15 years is highly heterogeneous and that malnutrition and parasitic infections are important contributors to the spatial variation in anaemia risk. The results presented in this study can help inform the integration of the current provincial malaria control programme with ancillary micronutrient supplementation and control of neglected tropical diseases such as urogenital schistosomiasis and STH infections.

Epidemiology of malaria, schistosomiasis, geohelminths, anemia and malnutrition in the context of a demographic surveillance system in northern Angola.

BACKGROUND: Malaria, schistosomiasis and geohelminth infection are linked to maternal and child morbidity and mortality in sub-Saharan Africa. Knowing the prevalence levels of these infections is vital to guide governments towards the implementation of successful and cost-effective disease control initiatives. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional study of 1,237 preschool children (0-5 year olds), 1,142 school-aged children (6-15 year olds) and 960 women (>15 year olds) was conducted to understand the distribution of malnutrition, anemia, malaria, schistosomiasis (intestinal and urinary) and geohelminths in a north-western province of Angola. We used a recent demographic surveillance system (DSS) database to select and recruit suitable households. Malnutrition was common among children (23.3% under-weight, 9.9% wasting and 32.2% stunting), and anemia was found to be a severe public health problem (i.e., >40%). Malaria prevalence was highest among preschool children reaching 20.2%. Micro-hematuria prevalence levels reached 10.0% of preschool children, 16.6% of school-aged children and 21.7% of mothers. Geohelminth infections were common, affecting 22.3% of preschool children, 31.6% of school-aged children and 28.0% of mothers. CONCLUSIONS: Here we report prevalence levels of malaria, schistosomiasis and geohelminths; all endemic in this poorly described area where a DSS has been recently established. Furthermore we found evidence that the studied infections are associated with the observed levels of anemia and malnutrition, which can justify the implementation of integrated interventions for the control of these diseases and morbidities.