Prevalence of electrocardiographic findings in elderly individuals: the Sao Paulo aging & health study.

Background: The determination of the prevalence of electrocardiographic alterations in the older age strata of the Brazilian population represents important information with clinical and epidemiological purpose.

Objective: To verify the prevalence rates of atrial fibrillation, enlarged Q/QS waves (Minnesota code 1.1-1.2) and left bundle branch block.

Methods: In a population-based study, 1,524 participants (921 women and 603 men) aged > 65 years and living in Sao Paulo, Brazil, were submitted to electrocardiographic assessment at rest as well as anthropometric and blood pressure measurements, in addition to fasting blood collection for the measurement of glycemia, total cholesterol and fractions.

Results: The age-adjusted prevalence for enlarged Q/QS waves was 12.1% (men, 17.2%; women, 9.6%), 2.4% for atrial fibrillation (men 3.9%; women, 2.0%); and 3.1% for left bundle branch block (men, 3.1%; women, 3.8%). For atrial fibrillation (both sexes), enlarged Q/QS waves (men) and left bundle branch block (women) there was an increase in frequency according to the age stratum. After adjusted for age, sex, diabetes mellitus and dyslipidemia, the odds ratio among the frequencies of enlarged Q/QS waves; arterial hypertension was 2.4 (95% CI: 1.4 -3.9) being 5.1 (95%CI: 1.8 -14.4) for women and 1.7 (95%CI: 0.95-3.1] for men.

Conclusion: The comparison of these data with those from other studies showed a high prevalence of enlarged Q/QS waves in this population, with a direct association with the prevalence of arterial hypertension.