 - Cardiovascular or cerebrovascular disease, such as history of myocardial infarction and ischemia, heart failure, angina, stroke, severe arrhythmias, or EKG abnormalities Wolf-Parkinson-White syndrome, Complete left bundle branch block, PR interval 120 ms or 200 ms, Prolonged QT interval corrected 500 ms, Cardiac arrhythmias as defined by PACs 3 per min or PVCs 1 per min. 