A common early sign of heart failure is shortness of breath with exercise, along with general fatigue and inability to do much activity. If fluid accumulates in the lungs, as may occur when the heart is not working effectively, there may be wheezing and coughing.
In boys who are already using a wheelchair most of the time, shortness of breath with exercise doesn't usually alert parents or physicians to the presence of a heart problem, since the boys aren't getting much exercise. In boys who are still walking as their heart failure is progressing, shortness of breath may occur as it would in other children with heart disease. Coughing may occur if the lungs fill with fluid.
Experts recommend that children with DMD and BMD be referred for evaluation of their cardiac function at an early age (some say even by 4 years old) and then have a yearly re-evaluation.
Many neurologists order regular electrocardiograms (ECGs) on boys with DMD or BMD, starting at a young age, so that they can watch for changes. The ECG, however, doesn't tell the doctor very much. It only gives the most general idea of how the heart is functioning.
These days, you'll likely be referred for another test of heart function, the echocardiogram. The echocardiogram is a more modern and much more specific tool to assess cardiac function. It uses ultrasound to view the heart and tells the doctor quite a lot about how the heart is working. It's painless and is usually covered by insurance. Some doctors recommend yearly echocardiograms for boys with DMD or BMD, starting at about age 4, or as soon as the condition is diagnosed.
Occasionally more elaborate and invasive tests, such as cardiac catheterization, may be ordered later if serious cardiac involvement is suspected. Cardiac catheterization involves going into the heart with a catheter (tube).
