Your doctor will diagnose cardiomyopathy based on your medical and family histories, a physical exam, and the results from tests and procedures.
                
Specialists Involved
                
Often, a cardiologist or pediatric cardiologist diagnoses and treats cardiomyopathy. A cardiologist specializes in diagnosing and treating heart diseases. A pediatric cardiologist is a cardiologist who treats children.
                
Medical and Family Histories
                
Your doctor will want to learn about your medical history. He or she will want to know what signs and symptoms you have and how long you've had them.
                
Your doctor also will want to know whether anyone in your family has had cardiomyopathy, heart failure, or sudden cardiac arrest.
                
Physical Exam
                
Your doctor will use a stethoscope to listen to your heart and lungs for sounds that may suggest cardiomyopathy. These sounds may even suggest a certain type of the disease.
                
For example, the loudness, timing, and location of a heart murmur may suggest obstructive hypertrophic cardiomyopathy. A "crackling" sound in the lungs may be a sign of heart failure. (Heart failure often develops in the later stages of cardiomyopathy.)
                
Physical signs also help your doctor diagnose cardiomyopathy. Swelling of the ankles, feet, legs, abdomen, or veins in your neck suggests fluid buildup, a sign of heart failure.
                
Your doctor may notice signs and symptoms of cardiomyopathy during a routine exam. For example, he or she may hear a heart murmur, or you may have abnormal test results.
                
Diagnostic Tests
                
Your doctor may recommend one or more of the following tests to diagnose cardiomyopathy.
                
Blood Tests
                
During a blood test, a small amount of blood is taken from your body. It's often drawn from a vein in your arm using a needle. The procedure usually is quick and easy, although it may cause some short-term discomfort.
                
Blood tests give your doctor information about your heart and help rule out other conditions.
                
Chest X Ray
                
A chest x ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. This test can show whether your heart is enlarged. A chest x ray also can show whether fluid is building up in your lungs.
                
EKG (Electrocardiogram)
                
An EKG is a simple test that records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart.
                
This test is used to detect and study many heart problems, such as heart attacks, arrhythmias (irregular heartbeats), and heart failure. EKG results also can suggest other disorders that affect heart function.
                
A standard EKG only records the heartbeat for a few seconds. It won't detect problems that don't happen during the test.
                
To diagnose heart problems that come and go, your doctor may have you wear a portable EKG monitor. The two most common types of portable EKGs are Holter and event monitors.
                
Holter and Event Monitors
                
Holter and event monitors are small, portable devices. They record your heart's electrical activity while you do your normal daily activities. A Holter monitor records the heart's electrical activity for a full 24- or 48-hour period.
                
An event monitor records your heart's electrical activity only at certain times while you're wearing it. For many event monitors, you push a button to start the monitor when you feel symptoms. Other event monitors start automatically when they sense abnormal heart rhythms.
                
Echocardiography
                
Echocardiography (echo) is a test that uses sound waves to create a moving picture of your heart. The picture shows how well your heart is working and its size and shape.
                
There are several types of echo, including stress echo. This test is done as part of a stress test (see below). Stress echo can show whether you have decreased blood flow to your heart, a sign of coronary heart disease.
                
Another type of echo is transesophageal (tranz-ih-sof-uh-JEE-ul) echo, or TEE. TEE provides a view of the back of the heart.
                
For this test, a sound wave wand is put on the end of a special tube. The tube is gently passed down your throat and into your esophagus (the passage leading from your mouth to your stomach). Because this passage is right behind the heart, TEE can create detailed pictures of the heart's structures.
                
Before TEE, you're given medicine to help you relax, and your throat is sprayed with numbing medicine.
                
Stress Test
                
Some heart problems are easier to diagnose when your heart is working hard and beating fast. During stress testing, you exercise (or are given medicine if you're unable to exercise) to make your heart work hard and beat fast while heart tests are done.
                
These tests may include nuclear heart scanning, echo, and positron emission tomography (PET) scanning of the heart.
                
Diagnostic Procedures
                
You may have one or more medical procedures to confirm a diagnosis or to prepare for surgery (if surgery is planned). These procedures may include cardiac catheterization (KATH-e-ter-i-ZA-shun), coronary angiography (an-jee-OG-ra-fee), or myocardial (mi-o-KAR-de-al) biopsy.
                
Cardiac Catheterization
                
This procedure checks the pressure and blood flow in your heart's chambers. The procedure also allows your doctor to collect blood samples and look at your heart's arteries using x-ray imaging.
                
During cardiac catheterization, a long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck and threaded to your heart. This allows your doctor to study the inside of your arteries for blockages.
                
Coronary Angiography
                
This procedure often is done with cardiac catheterization. During the procedure, dye that can be seen on an x ray is injected into your coronary arteries. The dye lets your doctor study blood flow through your heart and blood vessels.
                
Dye also may be injected into your heart chambers. This allows your doctor to study the pumping function of your heart.
                
Myocardial Biopsy
                
For this procedure, your doctor removes a piece of your heart muscle. This can be done during cardiac catheterization. The heart muscle is studied under a microscope to see whether changes in cells have occurred. These changes may suggest cardiomyopathy.
                
Myocardial biopsy is useful for diagnosing some types of cardiomyopathy.
                
Genetic Testing
                
Some types of cardiomyopathy run in families. Thus, your doctor may suggest genetic testing to look for the disease in your parents, brothers and sisters, or other family members.
                
Genetic testing can show how the disease runs in families. It also can find out the chances of parents passing the genes for the disease on to their children.
                
Genetic testing also may be useful if your doctor thinks you have cardiomyopathy, but you don't yet have signs or symptoms. If the test shows you have the disease, your doctor can start treatment early, when it may work best.