Electrocardiographic Profiles by sex in a cohort of healthy Vietnamese university students.

STUDY

OBJECTIVE

To establish sex-specific electrocardiographic (ECG) reference values in healthy Vietnamese late adolescents and characterize sex-based differences in repolarization patterns.

DESIGN

Cross-sectional observational study.

SETTING

University health screening program in Vietnam.

PARTICIPANTS

A total of 5127 first-year university students (58.6 % female; age 17-29 years), all asymptomatic and without known cardiovascular or metabolic disease.

INTERVENTIONS: None.

MAIN OUTCOME MEASURES: Standard ECG parameters (heart rate, PR interval, QRS duration, QTc, QRST angle), J-point elevation, ST-segment amplitude, and T-wave morphology in leads V1-V6, stratified by sex.

RESULTS

Significant sex differences were observed in all ECG parameters (p < 0.001). Females had higher heart rates (83 vs. 80 bpm), shorter PR intervals (138 vs. 140 ms), and longer QTc intervals (423 vs. 406 ms), while males showed longer QRS durations (90 vs. 80 ms) and narrower QRST angles. In precordial leads, males exhibited higher J-point and ST-segment amplitudes, especially in V2-V3, with the 98th percentile of ST60V2 reaching 0.40 mV. Anterior T-wave inversion (TWI) was more common in females, notably in V1 (71.3 % vs. 48.1 %) and V2 (2.5 % vs. 0.9 %). TWI beyond V2 was rare in both sexes.

CONCLUSION

This is the first large-scale study to define sex-specific ECG reference values in a Vietnamese cohort. Marked differences in repolarization patterns emphasize the importance of ethnicity- and sex-specific criteria to enhance diagnostic accuracy and avoid misinterpretation in Southeast Asian populations.