Prevalence of male and female patterns of early ventricular repolarization in the normal ECG of males and females from childhood to old age

Objectives This study was designed to establish the cause of electrocardiographic (ECG) pattern differences between genders. Background The male and female patterns of early ventricular repolarization in normal ECGs differ from each other. The male pattern displays a higher J-point amplitude and increased ST angle. The distribution of these patterns between genders has not been studied. Methods Normal ECGs of 529 males and 544 females, age 5 to 96 years, were subdivided into nine age groups in each gender. We designated the pattern as female if the J point was <0.1 mV in each of the leads V1 to V4, and as male if the J point was ≥0.1 mV and the ST angle ≥20° in at least one of the V1 to V4 leads; the pattern was indeterminate if the J point was ≥0.1 mV and the ST angle was <20°. Results Distribution of patterns was significantly different between genders (p < 0.001). In females, the patterns were distributed similarly from puberty to advanced age with about 80% prevalence of the female pattern. In males, the male pattern prevalence increased at puberty, reached 91% in the age group of 17 to 24 years and declined gradually with advancing age to 14% in the oldest males. The prevalence of indeterminate pattern was about 10% in both genders. Patterns were unchanged in 95% of 493 subjects who had ECGs recorded at separate times or at different heart rates. Conclusions Gender differences in early ventricular repolarization were caused by age-dependent changes in prevalence of the male pattern.