EFFECT OF BODY CHARACTERISTICS ON THE VARIABLES OF SIGNAL-AVERAGED ELECTROCARDIOGRAM IN HEALTHY TEENAGE SUBJECTS

Ventricular late potentials are obtained by signal-averaged surface electrocardiography. Late potentials ave been reported to be affected by body characteristics or left ventricular mass. To evaluate late potentials in relation to body characteristics, 52 healthy Japanese young volunteers (21 girls, 31 boys) aged 15-16 years were studied. QRS duration in men was significantly longer than in women. There were no significant differences in low-amplitude signal and root mean square voltage between women and men. When relations between signal-averaged electrocardiographic parameters and body characteristics were examined, QRS duration had positive linear correlations with weight and body mass index. The slope of QRS duration and weight relation, and QRS duration and body mass index relation was significantly steeper in men compared to those in women; a prolongation of QRS duration in men compared to women as weight and body mass index increased. Our results indicated that QRS duration in teenage healthy subjects should be used with caution because it is affected by gender.