Corticosteroids have been shown to be helpful in treating many diseases. The purpose of this study is to look at the effects of corticosteroids in babies who have had heart surgery and need blood pressure medicines in the intensive care unit after surgery. Our idea is that getting corticosteroids will allow us to decrease the amount of blood pressure medicines each patient needs and improve how they do after surgery. We also plan to do blood tests to help determine how the corticosteroids are working.