Browsing by Subject "Electrocardiography"
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Item Association of African Ancestry with Electrocardiographic Voltage and Concentric Left Ventricular Hypertrophy: The Dallas Heart Study(2020-05-01T05:00:00.000Z) Alame, Aya J.; Drazner, Mark H.; Garg, Sonia; Kozlitina, JuliaBACKGROUND: Compared with white individuals, black individuals have increased electrocardiographic voltage and an increased prevalence of concentric left ventricular (LV) hypertrophy. Whether environmental or genetic factors lead to these racial differences is unknown. OBJECTIVE: To determine whether proportion of genetically determined African ancestry among self-reported black individuals is associated with increased electrocardiographic voltage and concentric LV hypertrophy (LVH). METHODS: The Dallas Heart Study is a probability-based cohort study of English- or Spanish-speaking Dallas County, Texas, residents, with deliberate oversampling of black individuals. Participants underwent extensive phenotyping, which included electrocardiography (ECG), cardiac magnetic resonance imaging (CMR), and dual-energy radiography absorptiometry (DEXA) at a single center. Participants aged 18 to 65 years who enrolled in the Dallas Heart Study between July 2000 and December 2002, self-identified as black (n = 1251) or white (n = 826), and had ECG, CMR, and DEXA data were included in this analysis. Data were analyzed from June 2017 to September 2018. RESULTS: Of the 2077 participants included in the study, 1138 (54.8%) were women, and the mean (SD) age was 45.2 (9.9) years. Black race and African ancestry were individually associated with increased ECG voltage, LV concentricity^0.67, LVWT, and prevalent LVH in multivariable analyses adjusting for age, sex, systolic blood pressure, antihypertensive medication use, and body composition. When African ancestry and black race were entered together into multivariable models, African ancestry but not black race remained associated with ECG voltage, LVWT, LV concentricity0.67, and prevalent LVH. Among black participants, African ancestry remained associated with these 4 phenotypes (12-lead voltage: β, 0.05; P = .04; LVWT: β, 0.05; P = .02; LV concentricity^0.67: β, 0.05; P = .045; prevalent LVH: odds ratio, 1.2; 95% CI, 1.03-1.4; P = .02). CONCLUSION: Genetically determined African ancestry was associated with electrocardiographic voltage, measures of concentric LV remodeling, and prevalent LVH. These data support a genetic basis related to African ancestry for the increased prevalence of these cardiovascular traits in black individuals.Item Association of African Ancestry with Left Ventricular Hypertrophy Assessed by Electrocardiographic Voltage and Cardiac Magnetic Resonance: The Dallas Heart Study(2018-01-23) Alame, Aya J.; Garg, Sonia; Kozlitina, Julia; Ayers, Colby; Drazner, Mark H.INTRODUCTION: Left ventricular hypertrophy (LVH) is more common in blacks than whites, despite adjusting for differences in blood pressure. Whether environmental or genetic factors lead to this increased prevalence of LVH in blacks is unknown. If genetic factors are involved, we hypothesized that the proportion of African ancestry among self-reported blacks would be associated with an increased risk of LVH in this ethnic group. METHODS: Participants from the Dallas Heart Study underwent genotyping, an electrocardiogram (ECG), and Cardiac Magnetic Resonance (CMR) imaging. Ancestral admixture proportions were estimated using genetic markers (Illumina Exome Chip) and ADMIXTURE software assuming 3 ancestral populations. In this analysis, we included participants that self-identified as black or white (n=2077). First, we tested the association of genetically inferred African ancestry (AFR) and self-reported black race, separately, using multivariable linear regression models, with three LVH phenotypes: 12-lead ECG voltage, LV concentricity0.67 (LV mass/volume0.67, a marker of concentric LVH), and LV Wall Thickness (LVWT). Next, we entered both AFR and black race into the same models to determine if the association of black race with LVH would be accounted for by AFR. Finally, we tested the association of AFR with LVH phenotypes among self-reported blacks. RESULTS: The study cohort consisted of 1,251 black and 826 white participants. Black race and AFR were individually associated with ECG voltage, LV concentricity0.67, and LVWT (Table 1). When AFR and black race were entered together into multivariable models, AFR, but not black race, was significantly associated with the LVH phenotypes (Table 1). Among self-reported blacks, AFR remained significantly associated with these LVH phenotypes (Table 1). CONCLUSIONS: The association of black race with LVH phenotypes can be captured more robustly with a genetic estimate of African ancestry. Further, within blacks, the proportion of AFR was associated with LVH phenotypes. These data support a genetic basis, related to African ancestry, for the increased prevalence of LVH in blacks.Item Complete A-V block(1963-02-14) Bashour, Fouad A.Item [UT News](1985-12-01) Lyon, Pamela