[CK] QTc calculation.

QT ~ 1/HR.
(tachy => shorter QT)
So needs to be adjusted.
60-100: Bazett's method is ok. (<60: too low, >100: too high => lateralized)
<60 or > 100: Framingham or something else.

QTc prolongation(definition): male > 450, female > 470
1.See II or V5 or any lead(definite one) => 1 good lead with definite T-wave
(cf. bad T-wave = small U, flat, abnormal shape etc. But if U >1mm, should be included for calc.)
2.calculate successive(2-3 beats) and obtain maximum QTc.