Frequency of different electrocardiographic abnormalities in a large cohort of Spanish workers

AIMS: Our aim was to describe the electrocardiographic findings of a large sample of Spanish workers from several different employment sectors. METHODS AND RESULTS: Between May 2008 and November 2010, 13 495 consecutive 12-lead resting electrocardiograms (ECGs) were obtained during health examinations of working adults aged 16-74 years in 5 cities in different regions of Spain. Of those, 13 179 ECGs suitable for interpretation were included in this study. All tracings were classified by the same cardiologist, according to the Minnesota Code criteria. The mean age of the sample was 40 years, and 73.4% were male. Frequencies of complete right bundle branch block, complete left bundle branch block, and left ventricular hypertrophy were 1.1, 0.2, and 3.6%, respectively. Major Q wave abnormalities were observed in 1.7% of the subjects, T wave abnormalities in 0.7%, early repolarization in 2.4%, and other ST segment abnormalities in 0.2%. Atrial fibrillation was present in 0.08% of the workers and atrial flutter in 0.02%. Frequencies of the Wolff-Parkinson-White pattern, Brugada pattern, long QT pattern, and short QT pattern were 0.2, 0.068, 0.038, and 0.015%, respectively. CONCLUSION: This study shows the electrocardiographic findings of a large sample of Spanish workers from several different employment sectors. The frequencies of many ECG patterns related to an adverse prognosis (left ventricular hypertrophy, complete left bundle branch block, T wave abnormalities, ST segment abnormalities, and atrial fibrillation) were low.