Abstract 1325: Prevalence of Electrocardiographic Abnormalities in a Middle-Aged, Biracial Population: Coronary Artery Risk Development in Young Adults (CARDIA) Study
Background: Major and minor electrocardiographic (ECG) abnormalities are significant, independent risk markers for cardiovascular disease (CVD) events. Data are sparse regarding the prevalence of such ECG abnormalities in younger and middle-aged white and black men and women.
Methods: We studied participants from the Year 20 examination of the biracial CARDIA cohort. This examination included measurement of traditional risk factors and 12-lead ECGs. Differences in means or percentages for major and minor abnormalities (based on Minnesota codes, MC) compared to normal ECGs were tested using chi-square tests for categorical variables and t-tests or Wilcoxon rank-sum tests for continuous variables, as appropriate.
Results: The study sample consisted of 2585 participants (57% women and 44% blacks) mean age 45 years. This sample represents one of the largest and most contemporary biracial cohorts to examine ECG abnormalities to date. The prevalence of major and minor abnormalities, respectively, was significantly higher (all P<0.001) among black men and women (major 13.2% and minor 24.0% for black men, 8.3% and 17.1% for black women) compared to their white counterparts (6.1% and 9.2% for white men, 5.5% and 7.9% for white women, respectively) of the same sex. These differences were primarily due to higher QRS voltage and ST/T wave abnormalities among blacks (Table⇓). There was also a higher prevalence of major and minor Q waves (MC 1–1, 1–2, 1–3) than described by previous studies, particularly among white men (9.0%).
Conclusions: ECG abnormalities with significant prognostic implications are highly prevalent in middle-aged adults. Further investigation is warranted into the potential mechanisms of both the greater prevalence of ECG abnormalities among blacks as well as the overall high prevalence of major and minor Q waves among this middle-aged biracial cohort.