Relation of Cardiac Ventricular Repolarization and Global Cognitive Performance in a Community Population

Atherosclerosis is a risk factor for dementia. However, little is known about the association between cognitive performance and a widely used indicator of coronary heart disease, at rest electrocardiography. We identified 839 older residents (mean age 81 years, 58% black) from a geographically defined biracial community in Chicago, Illinois, who had undergone extensive cognitive performance testing and met the electrocardiographic eligibility criteria, including a QRS duration of <120 ms. We then examined multivariate regression coefficients that described the associations between global cognitive performance and 4 novel descriptors of ventricular repolarization waveforms. All analyses were adjusted for age, gender, education, and race. The T wave nondipolar voltage had a significant association with global cognitive performance (p = 0.01), and this association largely remained after adjustment for cardiovascular disease risk factors (p = 0.03). In contrast, global cognitive performance was not significantly associated with the rate-adjusted QT interval, the voltage change from the beginning to end of the ST segment in lead V₅, or the spatial angle between the mean QRS and T wave vectors. In conclusion, the strengths of the associations varied between the novel electrocardiographic descriptors of ventricular repolarization and global cognitive performance. Nevertheless, the significant association observed with T wave nondipolar voltage suggests that the cardiac effects of heart disease are associated with cognitive declines.