QT Interval Dispersion Behavior in Patients With and Without Obstructive Coronary Artery Disease Undergoing Exercise Test

Abstract Background: Stress test is used to detect coronary artery disease (CAD). The QTc interval dispersion (dQTc) is an electrocardiographic index of ventricular repolarization heterogeneity. Some researchers have linked transient myocardial ischemia induced by physical exertion with increased heterogeneity of ventricular repolarization measured by dQTc. Objectives: To study the patterns of dQT in patients with and without chronic obstructive CAD and to define a reliable cutoff point for dQT that could become a diagnostic criterion for myocardial ischemia. Methods: We retrospectively analyzed the electrocardiogram in resting and in exercise of 63 patients submitted to exercise test and cardiac catheterization. We divided the patients into three groups: true negative (VN), true positive (VP) and false positive (FP). VN: patients with coronary lesion lower than 70% and exercise test without myocardial ischemia; VP: individuals with stenosis greater than 70% in coronary arteries and a test suggestive of myocardial ischemia; FP: people with stenosis lower than 70% in the coronary arteries and stress test with ischemia criteria. Values of p < 0.05 were considered statistically significant. Results: Resting dQTc was not different among the three groups. However, for the dispersion of the QTc interval in exercise was, respectively, 47 ± 17 ms, 72 ± 42 ms, and 61 ± 31 ms for VN, VP and FP (p = 0.003). Conclusions: Obstructive chronic coronary disease patients have an increase in dQTc during exercise. Measurement of dQTc may be helpful in the diagnosis of myocardial ischemia in the stress test.

Prevalência de fatores de risco cardiovascular na população de Vitória segundo dados do VIGITEL e da Pesquisa Nacional de Saúde de 2013 / Prevalence of cardiovascular risk factors in the population of Vitória according to data from VIGITEL and the National Health Interview Survey of 2013

RESUMO: Objetivo: Comparar a prevalência de fatores de risco cardiovascular na população de Vitória (ES) em pesquisa autorreferida por contato telefônico (VIGITEL) ou por exames clínicos e laboratoriais realizados na Pesquisa Nacional de Saúde (PNS). Método: Os inquéritos foram realizados na população adulta de Vitória (≥18anos). No VIGITEL foram entrevistados 1996 indivíduos (homens = 38%). Na PNS foi feita visita domiciliar seguida de exames clínicos e laboratoriais em 318 indivíduos (homens = 48%) selecionados em 20setores censitários da cidade. Nos dois inquéritos, as prevalências foram ajustadas para a estrutura populacional estimada para o ano de 2013. Os dados são fornecidos como porcentagens e intervalo de confiança de 95% (IC95%). Resultados: Foram encontradas prevalências similares no VIGITEL e na PNS, respectivamente, para tabagismo (8,2%; IC95% 6,7 - 9,7% versus 10,0; IC95% 6,4 - 13,6%) e hipertensão (24,8%; IC95% 22,6- 27,0% versus 27,2%; IC95% 21,8 - 32,5%). Houve diferença estatística (p < 0,01) entre o VIGITEL e a PNS, respectivamente, para as prevalências de obesidade (16,8%; IC95% 14,1 - 18,1% versus 25,7%; IC95% 20,4- 30,9%) e colesterol elevado (≥ 200mg/dL) no sangue (20,6%; IC95% 18,6 - 22,6% versus 42,3%; IC95% 36,9- 47,7%). A prevalência de diabetes também foi maior (p < 0,05) na PNS (6,7 versus 10,7%). Conclusão: A prevalência populacional de hipertensão e tabagismo foi estimada adequadamente no VIGITEL. Isso não ocorreu com a obesidade por provável viés de informação do peso corporal no VIGITEL. Os dados mostram a necessidade de melhorar a cobertura diagnóstica das dislipidemias em vista da importância do controle desse fator de risco na prevenção primária das doenças cardiovasculares.

ABSTRACT: Objective: To compare the prevalence of cardiovascular risk factors in the adult population of Vitória, Espírito Santo, Brazil, in two surveys conducted by telephone interview (VIGITEL) or by clinic and laboratory exams during the National Health Interview Survey (NHIS). Method: Data were collected from adults (≥ 18 years). In VIGITEL, 1,996 subjects (males = 38%) were interviewed. In NHIS, home visit followed by clinical and laboratory tests was made with 318 individuals (males = 48%) selected in 20 census tracts of the city. The prevalence of risk factors was adjusted to the estimated population of the city in 2013. Data are shown as prevalence and 95% confidence interval (95%CI). Results: Similar values of prevalence were found in VIGITEL and NHIS, respectively, for smoking (8.2%; 95%CI 6.7-9.7% vs 10.0; 95%CI 6.4 - 13.6%) and hypertension (24.8%; 95%CI 22.6 - 27.0% vs 27.2%; 95%CI 21.8 - 32.5%). Statistical differences between surveys (p < 0.01) were found for diabetes (6.7%; 95%CI 5.6 - 7.9% vs 10.7%; 95%CI 7.1 - 14.5%), obesity (16.8%; 95%CI 14.1 - 18.1% vs 25.7%; 95%CI 20.4 - 30.9%) and high cholesterol (≥ 200mg/dL) (20.6%; 95%CI 18.6- 22.6% vs 42.3%; 95%CI 36.9 - 47.7%). The prevalence of diabetes was also higher (p < 0.01) in NHIS (6.7 vs 10.7%). Conclusion: Prevalence of smoking and hypertension, but not obesity, was adequately detected in VIGITEL, because there might have been information bias related to body weight during telephone interviews. Datashow the necessity to improve the diagnosis of dyslipidemias in primary care services, as the control of this risk factor is of utmost importance to prevent cardiovascular diseases.

Lipid disorders among Black Africans non-users of lipid-lowering medication

ABSTRACT Objective: Angola is a sub-Saharan African country where the population has scarce access to lipidlowering medication. We sought to determine the frequency of lipid disorders among Angolan nonusers of lipid-lowering medication. Material and methods: A cross-sectional descriptive study was carried out in a sample of 604 workers from the public sector. Blood pressure and anthropometric data were measured along with biochemical parameters including total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). LDL-C to HDL-C ratio (LDL-C/HDL-C) was obtained from LDL-C and HDL-C levels. Results: High frequencies of elevated blood pressure (44.8%), metabolic syndrome (20.2%), increased TC (39.2%) and increased LDL-C (19.3%) were found. Low HDL-C was more frequent in women (62.4% vs. 36.1%, p < 0.001). Isolated hypercholesterolemia was more frequent in men (9.6% vs. 2.5%, p < 0.001). Among men TC, TG, LDL-C and LDL-C/HDL-C ratio were higher and HDL-C was lower in obese than in low-weight and normal-weight participants. Among women TC, TG, LDL-C and LDL-C/HDL-C ratio were higher in obese than in normal-weight participants. Significant linear trend of increasing TC and LDL-C levels as age increased was detected for both genders (p for trend < 0.05). Conclusion: The results of our study showed a high frequency of lipid disorders in Angolan non-users of lipid-lowering medication.