Electrocardiograms of adult outpatients followed-up in basic health care units in the community of the South region of São Paulo City.

OBJECTIVE The electrocardiogram (ECG) is an important, available, and inexpensive diagnostic tool to assess cardiac symptoms. Few studies address the prevalence of ECG abnormalities or changes of a normal tracing in ECG in outpatients. Our objective was to evaluate ECGs of adult outpatients to determine whether changes from a normal tracing could disclose the patients' cardiovascular health status. METHODS We evaluated all elective ECGs obtained in adult outpatients, from January 2009 to January 2010, at a municipal hospital in the city of São Paulo, Brazil. Electrocardiography was performed with a 3-channel, 12-lead machine (Dixtal Cardio-page EP-3, Dixtal Biomedica, São Paulo, Brazil), and results were interpreted by a cardiologist. RESULTS Electrocardiography was performed in 3567 adult outpatients, 62.5% of whom were women, with a mean age of 51 years (standard deviation [SD] = 16 years). Of the 1918 patients whose ECGs showed abnormalities (mean age = 56 years, SD = 15 years), 1137 were women. Electrocardiographic changes were found in 1184 of the patients. Minor changes were found in 38.3% of patients. A total of 3133 changes were found in 1918 abnormal ECG results. There was a statistical difference related to sex and age, and abnormal ECG results were more frequent in men. There was a high prevalence of abnormal ECG results in the population studied. CONCLUSIONS There were more ECGs obtained from women; however, men and elderly patients more frequently had abnormal ECG results.