DbCM patients present clinically with shortness of breath on exertion due to decreased functional capacity of the heart muscle. Fortunately, DbCM can be diagnosed early in the disease through echocardiography. Another method to assess a person’s heart function is to look at NT-proBNP levels, a substance made by the heart, which can increase if there is physical stress on the heart. Health care professionals test NT-proBNP levels using a simple blood test to evaluate if a patient is at risk for heart disease.