Sex‐Specific Prevalence and Distribution of Electrocardiographic Variants in Healthy Vietnamese Freshmen

ABSTRACT Background Data on ECG characteristics and qualitative ECG variants in healthy young Vietnamese adults remain limited. We evaluated sex‐specific ECG differences and factors independently associated with common ECG variants in first‐year Vietnamese university students. Methods This cross‐sectional study included 6099 healthy students (3440 female [56.4%], 2659 male [43.6%]; mean age, 17.85 ± 0.65 years) undergoing standardized cardiovascular screening. Resting 12‐lead ECGs were analyzed for quantitative parameters and qualitative variants. Results All four core ECG parameters differed by sex (all p < 0.001). Females had higher heart rates (84.64 vs. 81.55 bpm) and longer QTc intervals (423.54 vs. 406.46 ms), whereas males had longer PR intervals (141.99 vs. 138.99 ms) and wider QRS complexes (91.44 vs. 80.81 ms). Males had higher prevalences of sinus arrhythmia (22.7% vs. 19.2%), early repolarization pattern (6.1% vs. 0.1%), right bundle branch block (4.4% vs. 0.3%), and sinus bradycardia (4.5% vs. 1.3%; all p < 0.001). Male sex was independently associated with early repolarization pattern (aOR, 37.7; 95% CI, 17.2–107) and right bundle branch block (aOR, 13.1; 95% CI, 7.55–25.2; both p < 0.001), but not sinus arrhythmia (aOR, 1.01; 95% CI, 0.84–1.21; p = 0.896). Conclusions ECG parameters and several qualitative variants differed by sex. These findings provide descriptive, population‐specific data on ECG characteristics and common qualitative variants in healthy young Vietnamese university students.