When I had my first heart event, I was surprised when the emergency room doctor ordered chest x-rays, but I later learned that this simple test can provide important information about the size and shape of your heart, if there are calcium deposits, and the condition of your lungs.
Enlargement or change in size
An enlarged heart results from damage or weakness to the heart muscle. Not only can an x-ray show if the heart is enlarged, it can show how the shape has altered. Different problems cause different changes in the heart. For example, one that's enlarged from mitral valve stenosis will look different from one that is enlarged from aortic stenosis.
Sometimes your body will produce calcium deposits in damaged or diseased heart tissue. Calcium deposits can also be found in diseased valves, arteries, or the sac that surrounds the heart (pericardium). These deposits will be visible on the x-ray. Sometimes calcium deposits are the first sign that there is heart disease.
Conditions of the lungs that are related to heart disease can be picked up with a chest x-ray. These include swelling in the veins in the lungs and accumulation of fluid (pulmonary edema).
What to expect
Most people have had x-rays so the procedure is not a mystery. It's painless and other than the possibility of having to wait for your turn, it doesn't take long. You will likely be asked to take off clothes and jewelry from the waist up and put on a hospital gown.
There is a very small amount of radiation in any x-ray but the benefits of the diagnostic capabilities greatly outweighs the risk. Care is taken to protect you from unnecessary exposure. If there is any chance a woman is pregnant, she should tell her doctor so the appropriate precautions can be taken.
Further information on heart tests can be found in the Mayo Clinic Heart Book, Revised Edition: The Ultimate Guide to Heart Health.