Symptoms and Diagnosis of Cardiomyopathy

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It’s important to identify those who may be at high risk for cardiomyopathy. After all, some people with cardiomyopathy never have signs or symptoms. Others don’t have signs or symptoms in the early stages of the disease.

If people without symptoms recognize their heightened risk for cardiomyopathy, there’s a better chance of diagnosing it early, when treatment may be most effective.

Signs and symptoms of cardiomyopathy include:

  • Shortness of breath or trouble breathing, especially with physical exertion
  • Fatigue
  • Swelling in the ankles, feet, legs, abdomen and veins in the neck
  • Dizziness
  • Lightheadedness
  • Fainting during physical activity
  • Arrhythmias (irregular heartbeats)
  • Chest pain, especially after physical exertion or heavy meals
  • Heart murmurs (unusual sounds associated with heartbeats)

Signs and symptoms of heart failure usually occur in the later stages of cardiomyopathy, as the heart weakens.

How is cardiomyopathy diagnosed?

Your doctor will diagnose cardiomyopathy based on your medical history, family history, a physical exam and diagnostic test results.

Often, a cardiologist or pediatric cardiologist diagnoses and treats cardiomyopathy. These doctors specialize in heart diseases.

Medical and family histories

Your doctor will want to learn about your medical history as well as any signs and symptoms you may have. Your physician will also want to know whether anyone in your family has been diagnosed with cardiomyopathy, heart failure or cardiac arrest.

Physical exam

Using a stethoscope, your doctor will listen to your heart and lungs for sounds that may suggest cardiomyopathy. Particular 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.

Certain 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.

Diagnostic tests

Your doctor may recommend one or more of the following tests to diagnose cardiomyopathy:

  • Blood tests: A small amount of blood is taken usually drawn from a vein in your arm using a needle.
  • Chest X-ray: A chest X-ray takes pictures of the organs and structures inside your chest, and can show whether your heart is enlarged. It can also reveal whether fluid is building up in your lungs.
  • Electrocardiogram (EKG or ECG): An EKG records the heart’s electrical activity, showing how fast the heart is beating and whether its rhythm is steady or irregular. An EKG can be used to detect cardiomyopathy as well as other problems, including heart attacks, arrhythmias (irregular heartbeats) and heart failure. To diagnose heart problems that come and go, your doctor may have you wear a portable EKG monitor.
  • Holter and event monitors: Both of these are portable devices that record your heart’s electrical activity during 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.
  • Echocardiogram (Echo): An echocardiogram (echo) is a test that uses sound waves to create a moving picture of your heart. It shows how well your heart is working as well as its size and shape. There are several types of echocardiography, including “stress echo,” which is administered as part of a stress test. Another type, transesophageal echo (or TEE), provides a view of the back of the heart.
  • Stress test: In a stress test, the aim is to make your heart work hard (and beat fast) while tests are performed. These tests may include nuclear heart scanning, echo, and positron emission tomography (PET) scanning. You’ll be asked to walk in place on an inclined treadmill. If you are unable to exercise, you may be given medicine to simulate the effects of exertion.

Diagnostic procedures

Confirming a diagnosis may involve one or more medical procedures. Or, if surgery is planned, a diagnostic procedure may be performed in preparation for surgery. Such diagnostic procedures may include:

  • Cardiac catheterization: Cardiac catheterization checks the pressure and blood flow in your heart’s chambers. In this procedure, a long, thin, flexible tube called a catheter is inserted through a blood vessel and threaded to the heart. This allows the doctor to collect blood samples and check your heart’s arteries for blockages using X-ray imaging.
  • Coronary angiography (PDF): This procedure often is done during cardiac catheterization. Dye that can be seen on an X-ray is injected into your coronary arteries. The dye allows your doctor to study blood flow within your heart and blood vessels.
  • Myocardial biopsy: In this procedure, your doctor removes a piece of your heart muscle, which can be done during cardiac catheterization. The muscle is studied under a microscope to see whether changes in cells have occurred, which may suggest cardiomyopathy.
  • Genetic testing: Your doctor may suggest genetic testing to look for signs of cardiomyopathy in your parents, brothers and sisters or other family members. Genetic testing can show how the disease runs in families and can reveal the chances of parents passing the genes for the disease on to their children. Genetic testing may also be useful if your doctor suspects that you may have cardiomyopathy, but you don’t yet exhibit signs or symptoms.


Source: National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services(link opens in new window).