Anyone thought to have a heart disorder has chest x-rays Plain X-Rays X-rays are high-energy radiation waves that can penetrate most substances (to varying degrees). In very low doses, x-rays are used to produce images that help doctors diagnose disease. In high... read more taken from the front and the side. Typically, the person is standing upright, but chest x-rays can be done with people lying in bed if they cannot stand. A machine is then used to beam x-rays through the person's body and record a picture on an x-ray film. The test is painless.
The x-rays show the shape and size of the heart and the outline of the large blood vessels in the lungs and chest. Abnormal heart shape or size and abnormalities, such as calcium deposits within blood vessels, are readily seen. Chest x-rays also can detect information about the condition of the lungs, particularly whether blood vessels in the lungs are abnormal and whether there is fluid in or around the lungs.
X-rays can detect enlargement of the heart, which is often due to heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more 
or a heart valve disorder Overview of Heart Valve Disorders Heart valves regulate the flow of blood through the heart's four chambers—two small, round upper chambers (atria) and two larger, cone-shaped lower chambers (ventricles). Each ventricle has... read more 
. X-rays can sometimes be helpful in diagnosis of constrictive pericarditis Overview of Pericardial Disease Pericardial disease affects the pericardium, which is the flexible two-layered sac that envelops the heart. The pericardium helps keep the heart in position, helps prevent the heart from overfilling... read more 
by detecting calcium deposits of the sac that envelops the heart (pericardium).
The appearance of blood vessels in the lungs is often more useful in making a diagnosis than the appearance of the heart itself. For instance, enlargement of the pulmonary arteries (the arteries that carry blood from the heart to the lungs) and narrowing of the arteries within the lung tissue suggest high blood pressure in the pulmonary arteries, which may lead to thickening of the muscle of the right ventricle (the lower heart chamber that pumps blood through the pulmonary arteries to the lungs).
