Associations between QT interval subcomponents, HIV serostatus, and inflammation.

BACKGROUND: The total QT interval comprises both ventricular depolarization and repolarization currents. Understanding how HIV serostatus and other risk factors influence specific QT interval subcomponents could improve our mechanistic understanding of arrhythmias. METHODS: Twelve-lead electrocardiograms (ECGs) were acquired in 774 HIV-infected (HIV+) and 652 HIV-uninfected (HIV-) men from the Multicenter AIDS Cohort Study. Individual QT subcomponent intervals were analyzed: R-onset to R-peak, R-peak to R-end, JT segment, T-onset to T-peak, and T-peak to T-end. Using multivariable linear regressions, we investigated associations between HIV serostatus and covariates, including serum concentrations of inflammatory biomarkers such as interleukin-6 (IL-6), and each QT subcomponent. RESULTS: After adjustment for demographics and risk factors, HIV+ versus HIV- men differed only in repolarization phase durations with longer T-onset to T-peak by 2.3 ms (95% CI 0-4.5, p < .05) and T-peak to T-end by 1.6 ms (95% CI 0.3-2.9, p < .05). Adjusting for inflammation attenuated the strength and significance of the relationship between HIV serostatus and repolarization. The highest tertile of IL-6 was associated with a 7.3 ms (95% CI 3.2-11.5, p < .01) longer T-onset to T-peak. Age, race, body mass index, alcohol use, and left ventricular hypertrophy were each associated with up to 2.2-12.5 ms longer T-wave subcomponents. CONCLUSIONS: HIV seropositivity, in combination with additional risk factors including increased systemic inflammation, is associated with longer T-wave subcomponents. These findings could suggest mechanisms by which the ventricular repolarization phase is lengthened and thereby contribute to increased arrhythmic risk in men living with HIV.