Abstract: To evaluate the feasibility of Q-T_d measurements under circumstances of body surface potential mapping(BSPM), QT_d^p(dispersion of interval of Q-wave onset to T-wave peak) was observed by using a computerized automatic mapping system in 80 normal individuals. The findings were compared with the 12-lead Q-T_d(the dispersion of Q-T interval). It was shown that: ① Q-T^p, Q-T_d^p, Q-T_c1d^p(corrected by Bazzett formula) and Q-T_c2d^p(corrected by Fridercia formula) were (292.69±37.75) ms, (36.77±7.40) ms, (40.23±9.04) ms and (40.11±7.73) ms respectively. ② Q-T_d and Q-T_c measured by BSPM and 12-lead ECG correlated well each other. ③ The differences of above parameters between three age groups(18～35 years, 36～60 years and 61～70 years) were not significant. ④ Q-T^p of female was longer than that of male(P<0.05), no significant difference was found in other parameters. In conclusion, Q-T_d^p measurement by BSPM might be more accurate and reliable than 12-lead ECG. The normal value of Q-T_d^p was less than 52 ms in this study.

Key words: body surface potential mapping, Q-T^p interval, Q-T^p interval dispersion, normal individuals