- QTc with Bazett's correction that is unmeasurable, or greater than or equal to 460 msec on screening ECG. If a patient has QTc greater than or equal to 460 msec on screening ECG, a second screen ECG may be repeated at least 24 hours apart. The average QTc from the 2 screening ECGs must be less than 460 msec in order for the patient to be eligible for the study. If the patient meets eligibility requirements in this way, the "baseline" QTc for this patient will be the average of the 3 ECGs (screen 1, screen 2, and pre-1st dose).