Electrical Heterogeneity in Hispanic Background Subpopulations: The HCHS/SOL.

Background: The Hispanic/Latino population is not uniform. Prevalence and clinical outcomes of cardiac arrhythmias in ethnic background subgroups are variable, but the reasons for differences are unclear. Vectorcardiographic Global Electrical Heterogeneity (GEH) has been shown to be associated with adverse cardiovascular outcomes.

Objectives: The purpose of this study was to compare GEH in Hispanic/Latino background subpopulations. We hypothesized that ethnicity category moderates an association of prevalent cardiovascular disease (CVD) with GEH.

Methods: Cross-sectional analysis of the HCHS/SOL (Hispanic Community Health Study/Study of Latinos) included 15,684 participants (mean age 41 years; 38% Mexican, 20% Cuban, 16% Puerto Rican, 10% Dominican, 7% Central American, 5% South American, 4% mixed Hispanic/Latino background). Acculturation and socioeconomic data were collected. GEH was measured as spatial QRS-T angle, spatial ventricular gradient (SVG) azimuth, SVG elevation, SVG magnitude, and sum absolute QRST integral. Linear regression models included interaction terms of ethnic background category by CVD and were adjusted for age, sex, education attainment, hypertension, diabetes, smoking, dyslipidemia, obesity, chronic kidney disease, physical activity, diet quality, heart rate, and rhythm.

Results: The adjusted spatial QRS-T angle was significantly ( < 0.0001) narrower in Dominican background (-3.4°[95% CI -5.0° to -1.7°]) as compared to a total mean. SVG azimuth pointed farther posteriorly in Dominican (+2.9 [95% CI: 1.6-4.2]) and Puerto Rican (+3.8 [2.4-5.2]), but farther anteriorly in South American (-2.9 [95% CI: -4.4 to -1.4]) and Mexican (-3.5 [95% CI: -4.3 to -2.6]) vs total mean. An association of coronary heart disease with GEH was especially strong in Cuban background subpopulation.

Conclusions: In CVD-free Hispanic/Latino subpopulations, cardiovascular risk factors do not fully explain GEH differences across ethnic background categories, which likely reflect unmeasured health disparities.