- History or presence of an abnormal ECG which, in the investigator's opinion, is clinically meaningful. Screening corrected QT interval (QTc) > 480ms is excluded. Subjects with left bundle branch block are excluded. For those subjects with an intraventricular conduction delay (QRS > 120 ms) and QTc interval >480ms, they can be enrolled if JT interval (JTc) is ≤340ms.