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Background Few studies to date have described the prevalence of electrocardiographic (ECG) abnormalities in a biracial middle-aged cohort. Methods and Results Participants underwent measurement of traditional risk factors and 12-lead ECGs coded using both Minnesota Code (MC) and Novacode (NC) criteria. Among 2585 participants, of whom 57% were women and 44% were black (mean age 45 years), the prevalence of major and minor abnormalities were significantly higher (all P<0.001) among black men and women compared to whites. These differences were primarily due to higher QRS voltage and ST/T wave abnormalities among blacks. There was also a higher prevalence of Q waves (MC 1-1, 1-2, 1-3) than described by previous studies. These racial differences remained after multivariate adjustment for traditional cardiovascular (CV) risk factors. Conclusions Black men and women have a significantly higher prevalence of ECG abnormalities, independent of traditional CV risk factors, than whites in a contemporary cohort middle-aged participants.

The growth of losses, secondary kinetic energy, and streamwise vorticity have been studied in a high turning rotor cascade. Negative vorticity associated with the passage vortex agreed well with predictions of classical secondary flow theory in the early part of the blade passage. However, toward the exit, the distortion of the flow by the secondary velocities rendered the predictions inaccurate. Areas of positive vorticity were associated with the feeding of loss into the bulk flow and have been related to separation lines observed by surface flow visualization.

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Background Early repolarization (ER), a common electrocardiographic phenotype, has been associated with increased mortality risk in middle-aged adults. Data are sparse on long-term follow-up and outcomes associated with ER in younger adults. Methods and Results We prospectively examined 5,039 participants (mean age 25 years at baseline, 40% black) from the CARDIA cohort over 23 years. Twelve-lead electrocardiograms were recorded and analyzed at Years 0, 7 and 20 and coded as definite or probable ER using a standardized algorithm. Cox regression was used, and models were adjusted for important baseline and clinical covariates. Kaplan-Meier curves were created for presence of ER and total mortality and cardiovascular (CV) mortality. Participants with ER were more likely to be black, male, smoke, have higher systolic blood pressure, lower heart rate, and BMI, and also higher exercise duration, and longer PR, QRS and QT intervals. ER was associated with total mortality (HR1.77, 1.38–2.28, p<0.01), and CV mortality (HR 1.59, 1.01–2.50, p=0.04) in unadjusted analyses, but adjustment for age, sex, and race attenuated associations almost completely. Sex-race stratified analyses showed no significant associations between ER and outcome for any of the subgroups except blacks. Conclusions The presence of ER at any time point over 23 years of follow-up was not associated with adverse outcomes. Black race and male sex confound the unadjusted association of ER and outcomes, with no race-sex interactions noted. Further studies are necessary to understand the factors associated with heightened risk of death in those who maintain ER into and beyond middle age.