Q—T间期(如T波后出现U波则称Q—T—U间期)代表心室除极与复极所需的全部时间,也称为电收缩时间。Q—T间期随心率而变动,故需根据心率加以矫正,一般采用Baz-ett公式,Q—T_c=Q—T/(秒)(R—R(秒))~(1/2),超过0.425表示Q—T间期延长,Simonson还根据年龄予以矫正,Q-T=0.2423+(R—R)~(1/2)+0.0003×年龄。ST段延长、T波起始及终止延迟、T波或TU增宽,均使Q—T间期延长。心电图与病理对照研究证明,Q—T间期 Q-T interval (such as T waves appear after U wave is called Q-T-U interval) on behalf of ventricular depolarization and repolarization all the time required, also known as electrical contraction time. Q-T interval changes with the heart rate, it is necessary to be corrected according to heart rate, the general use of Baz-ett formula, Q-T_c = Q-T / (seconds) Exceed 0.425 means prolongation of Q-T interval, Simonson also correct according to age, QT = 0.2423 + (R-R) ~ (1/2) + 0.0003 × age. ST-segment extension, T-wave initiation and termination delay, T-wave or TU broadening, all extend the Q-T interval. ECG and pathology control studies have shown that Q-T interval