- Electrocardiogram reading considered outside the normal limits by the investigator (e.g. abnormally prolonged QTc corrected by Fridericia's method > 450 msec in males, on ECG tracing). The following conduction abnormalities may confound QTc analysis and should be avoided if possible: PR > 220 msec, 2nd or 3rd degree AV block, intraventricular conduction delay with QRS > 120 msec, left branch bundle block, right branch bundle block or Wolff-Parkinson-White syndrome;