Prevalence rates of major and minor electrocardiogram abnormalities in the Singapore general population.

A cross-sectional survey on the general population was carried out in Singapore, with each of the 2143 persons (Chinese, Malays and Indians) aged 18 to 69 years having a 12-lead resting electrocardiogram (ECG). The tracings were coded according to the Minnesota Code with major abnormalities being Q wave changes (1-1 and 1-2), complete atrio-ventricular (A-V) block (6-1), and left bundle branch block (7-1) and minor abnormalities being lesser Q wave changes (1-3), ST depression of at least 1 mm (4-1), and T wave inversion of at least 1 mm (5-1 and 5-2). In all age groups the prevalence rates of any major abnormality were higher in males than females. In the age-adjusted 18-69 age group the prevalence rates in males and females were 2.0% and 0.5% respectively (P = 0.001). The prevalence rates of any minor abnormality (without any major abnormality) were higher in females than males in all age groups and in the age-adjusted 18-69 age group the prevalence rates in males and females were 3.5% and 5.4% respectively (P = 0.027). The prevalence rates of any minor abnormality (without any major abnormality) in the 18-29 age group in males and females were 2.2% and 4.7% respectively, indicating that these proportions of the population have minor abnormalities as a normal physiological variant. It is estimated in the 50-69 age group that 33.8% of males and 50.0% of females with any minor abnormality (without any major abnormality) have these changes as a normal physiological variant.