 - History of significant cardiovascular disease unless the disease is well-controlled or history of myocardial infarction in the past 6 months. Significant cardiac diseases includes secondthird degree heart block; significant conduction abnormalities, significant ischemic heart disease; QTc interval 480 msec at baseline using Bazetts formula and read by local cardiologist; poorly controlled hypertension; congestive heart failure of New York Heart Association NYHA Class II or worse slight limitation of physical activity; comfortable at rest, but ordinary physical activity results in fatigue, palpitation, or dyspnea and inability to tolerate intravenous hydration necessary for study therapy administration. 