Dear Dr. Roach: I am a 66-year-old male who gets shortness of breath when walking up a hill or on a trail. I had a stent put in in 2002, and I had a stress test done. My doctor said it was fine, but he said I just had shortness of breath. It seems that it happens only when I am walking. I just went to my lung doctor, and he said my lungs are OK. Can shortness of breath come from coronary artery disease? Should I be concerned?
Dear W.S.: Shortness of breath is indeed a common symptom of coronary artery disease, but that does not mean your shortness of breath is due to coronary artery disease. There are many causes, which usually spring from one of four systems: the heart, lungs, blood or neurologic/psychiatric (or, central nervous) system.
Shortness of breath can be a symptom of angina, where the blood supply to the heart cannot keep up with its demands. It is the most common symptom of heart failure, where the output of the heart is insufficient for the demands of the body, especially when the demands of the body are high (i.e., during exercise).
Any condition of the lung that affects air exchange (that’s essentially any lung disease) can cause shortness of breath. A severe low blood count (anemia) can cause shortness of breath, because even with normal heart and lungs, oxygen can’t be delivered to the tissues that need it without enough blood to carry it. The brain can erroneously sense shortness of breath, especially in anxiety disorders.
In someone with known heart disease (you have a stent, so you are known to have CAD), it is rational to think first of a new blockage (or a blocked stent). A stress test is the usual test that looks for blockages, and it is very sensitive in finding blockages, though not perfect. Sometimes a cardiologist will order the definitive test — coronary angiography — to look for a blockage, if the concern is high enough. An echocardiogram is the best test used to diagnose heart failure, while a simple complete blood count can evaluate anemia.
It is common that we do not find a reason for shortness of breath. My experience is that what doctors call “cardiac deconditioning” and everyone else calls “out of shape” is the most common cause. Once common problems have been excluded, I usually recommend an exercise program. For people who exert themselves on an occasional basis (say, you take the hill trail only once a week), then some shortness of breath is expected.
Email questions to ToYourGoodHealth@med.cornell.edu.