Gender-Specific Differences In Electrocardiographic Recordings

Abstract

Studies have reported gender differences in electrocardiographic (ECG) recordings. Specifically, females are reported to have higher heart rates (HR), shorter PR intervals, longer QT intervals, lower ECG voltages, ST segment deviations, and a greater prevalence of sinus arrhythmia. Yet, many studies report the need for more research on differences in ECG recordings in male and females. PURPOSE: To examine whether there are significant gender differences in ECG recordings. METHODS: A total of 104 active participants, including 34 male (M, age = 24.6 ± 10.3 yrs) and 70 females (F, age = 26.6 ± 12.2 yrs) were included in this study. Participants were excluded from the study if they had a positive disease history or if they indicated use of any medication that is reported to effect cardiac conduction. A standard 12-lead ECG was recorded after 5 minutes of supine rest. ANOVA was used to test for a significant effect of gender on heart rate (HR), PR interval, QTc interval, P axis, QRS axis, T axis, QRS/T Angle and on voltage criteria for left ventricular hypertrophy (LVH) based on the Cornell product (CP) and Sokolow-Lyon (SL). RESULTS: Significant differences between M and F subjects were found for HR (M = 58.1 ± 12.2; F = 66.4 ± 11.3 bpm, p < .05), PR interval duration (M = 167.7 ± 30.9; F = 153.3 ± 26.7 ms, p < .05), QTc duration (M = 385.1 ± 25.8; F = 391.4 ± 20.4 ms, p < .05), CP criterion (M = 1185.0 ± 734.6; F = 521.8 ± 360.5 mVms, p < 0.001) and SL criterion (M = 36.6 ± 9.9; F = 23.6 ± 7.6 mm, p < 0.001) for LVH. There were no significant differences between M and F in the P axis, QRS axis, T axis, or QRS/T Angle. The M subjects had a greater prevalence of sinus arrhythmia (M = 23.5%; F = 18.6%), 1st degree atrioventricular block (M = 11.8%; F = 2.9%), and early repolarization (M = 14.7%; F = 1.4%) compared to the F subjects. CONCLUSIONS: Similar to other studies, we found that the male participants had a lower heart rate, longer PR interval, shorter QTc interval, and overall greater ECG voltages in comparison to female participants. However, we did not find a significant gender effect on P axis, QRS axis, T axis or QRS/T angle. The molecular basis for gender differences in the electrical activity of the heart has not been clearly determined but warrants further study.