Análise de eletrocardiogramas digitais de pacientes assistidos pela rede de teleassistência de Minas Gerais

Abstract

Background: Knowledge of reference values for sex and age group for primary care patientsis mandatory for establishing which patients have abnormal exams. No studies assessed the reference standards for Latin American population. The purpose of this study was to establish the reference values for electrocardiogram for healthy pediatric and adult primary care patients from Minas Gerais. Methods: This retrospective observational study assessed all the consecutive 12-lead digital electrocardiograms of primary care patients of at least 1 year old in Minas Gerais state, Brazil, between January 2010 and January 2015. Exclusion criteria included: 1) electrocardiograms with technical problems or selected abnormalities; 2) patients with selected self-declared comorbidities or drug use; 3) exams from repeated patients. The University of Glasgow ECG Analysis Program was used to automatically interpret the exams. For each variable, the 1st, 2nd, 50th, 98th and 99th percentiles were determined and 2nd and 98th percentiles were considered, respectively, the lower and upper limits of normality. Our results were compared to four other studies of different populations. Results: A total of 1,493,905 ECGs were recorded, 1,007,891 were excluded and 486,014 were analyzed. This large study provided reference values for heart rate, P, QRS and T frontal axis, P and QRS overall duration, PR and QT overall intervals and QTc corrected by Hodges, Bazett, Fridericia and Framingham methods. Overall, our results were similar to other studies performed in different populations but there were differences in extreme ages and specific values. Conclusions: We provided reference values for Brazilians older than 1 year old. Our results are comparable to studies performed in different populations.