- QTc prolongation (defined as a QTc interval > 450 msec for males and >470 msec for females) or other significant ECG abnormalities; NOTE: patients with clinically significant cardiac conduction abnormalities should be excluded, these include left bundle branch block (LBBB), 2nd or 3rd degree AV block, bifascicular block, sick sinus syndrome, Wolff-Parkinson-white syndrome, sinus bradycardia (< 50bpm); however, patients with asymptomatic right bundle branch block (RBBB) or 1st degree AV block, in the absence of known cardiac disease (e.g. coronary, valvular) are not excluded