Patient education: Dilated cardiomyopathy (The Basics)

What is dilated cardiomyopathy? — Dilated cardiomyopathy is a condition in which the heart muscle weakens and does not pump blood as well as it should.

The heart's main pumping chamber is called the left ventricle. In people with dilated cardiomyopathy, the space inside the left ventricle gets bigger. The space inside the right ventricle might also get bigger (figure 1). When the heart does not pump blood as well as it should, this can lead to a problem called "heart failure."

The term "heart failure" is misleading. If your doctor tells you that you have heart failure, it does not mean your heart has stopped working. It just means that your heart has trouble keeping up with your body's demand for blood and oxygen (which is carried in the blood). But it is still working.

What are the symptoms of dilated cardiomyopathy? — At first, dilated cardiomyopathy often does not cause symptoms. But as the condition gets worse, it can cause:

●Trouble breathing, especially during exercise

●Trouble breathing when lying down or asleep

●Trouble doing physical activity or exercise

●Swelling in the feet, ankles, or legs (figure 2)

Is there a test for dilated cardiomyopathy? — Yes. If your doctor or nurse suspects you have cardiomyopathy, they will ask you questions and do an exam. They might also order 1 or more of these tests:

●A chest X-ray – A chest X-ray shows if there is fluid in the lungs. It also shows the general shape and size of the heart and large blood vessels in the chest.

●An electrocardiogram (ECG) – This test measures the electrical activity in your heart. It can show if your heart beats in a normal rhythm and if you have had a heart attack in the past.

●An echocardiogram (or "echo" for short) – An echo uses sound waves to create an image of the heart. This test allows doctors to measure the walls and chambers of the heart, see how well the heart is pumping, and see how well the heart valves are working. (Heart valves are flaps of tissue that open and close like swinging doors. They help keep blood flowing in the right direction.)

●A stress test – During a stress test, you might be asked to run or walk on a treadmill while you also have an ECG. Physical activity makes the heart pump faster and increases the heart's need for blood. This test helps doctors see if the heart is getting enough blood. If you cannot walk or run, your doctor might do this test by giving you a medicine to make your blood vessels widen or make your heart pump faster.

●Cardiac catheterization (also called "cardiac cath") – During this test, the doctor puts a thin tube into a blood vessel in your neck, leg, or arm. Then they move the tube up to your heart. When the tube is in your heart or blood vessels, they will take measurements. The doctor might also put a dye that shows up on an X-ray into a tube. This can show if any of the arteries in your heart are narrowed or blocked. This part of the test is called "coronary angiography." In some cases, the doctor will also take a tiny piece of heart muscle (a "biopsy"). This can help the doctor find the cause of your cardiomyopathy.

How is dilated cardiomyopathy treated? — Treatment for dilated cardiomyopathy depends on what is causing it and how severe it is. For example, in people who have cardiomyopathy caused by alcohol use, an important part of treatment is avoiding alcohol. If dilated cardiomyopathy is causing heart failure, the treatment is generally similar to that for other causes of heart failure.

More on this topic

Patient education: Heart failure (The Basics)
Patient education: Hypertrophic cardiomyopathy in adults (The Basics)
Patient education: Echocardiogram (The Basics)
Patient education: ECG and stress test (The Basics)

Patient education: Dilated cardiomyopathy (Beyond the Basics)
Patient education: Heart failure (Beyond the Basics)
Patient education: Hypertrophic cardiomyopathy (Beyond the Basics)