Isuprel is a bronchodilator that works by relaxing muscles in the airways to improve breathing. Isuprel is used for the treatment of conditions such as emphysema, bronchitis, asthma, congestive heart failure, heart attack, blood vessel problems and heart block. Isuprel opens breathing passages and makes it easier to breath. Isuprel helps the heart to pump blood more effectively by relaxing the airway to help a patient's breath more easily. More frequently, Isuprel is used for heart issues than asthma.