Prevalence of normal electrocardiograms in primary care patients.

Objective: Knowing the proportion the proportion of normal and abnormal electrocardiograms (ECGs) in primary care patients allows us to estimate the proportion of exams that can be analyzed by the general practitioner with minimal training in ECG interpretation, in addition to being epidemiologically relevant. The objective of this study is to assess the prevalence of normal ECGs in primary care patients.

Methods: All digital ECGs analyzed by the cardiologists of Telehealth Network of Minas Gerais (TNMG) in 2011 were evaluated. TNMG is a public telehealth service that provides support to primary care professionals in 662 municipalities in the state of Minas Gerais, Brazil.

Results: During the study period, 290,795 ECGs were analyzed (mean age 51 ± 19 years), 57.6% were normal. This proportion was higher in women (60.1 vs 57.6%, p <0.001) and lower in patients with hypertension (45.8% vs 63.2%, p <0.001) or diabetes (43.3% vs 63.2%, p <0.001). A progressive reduction in the prevalence of normal ECG with increasing age was observed. Among the ECGs of patients under investigation for chest pain, 58.7% showed no abnormalities.

Conclusion: The prevalence of normal ECGs in primary care patients is higher than 50% and this proportion decreases with age and comorbidities. Most ECGs performed for investigation of chest pain in primary care shows no abnormality.