5. Significant cardiovascular disease such as uncontrolled or symptomatic untreated arrhythmias, congestive heart failure, or myocardial infarction within 6 months of screening, or any Class 3 or 4 cardiac disease as defined by the New York Heart Association Functional Classification, or QTc > 480 msec at screening. Exception: Subjects with controlled, asymptomatic atrial fibrillation during screening are allowed to enroll on study.