Dilated cardiomyopathy is a disease of the heart muscle, usually starting in your heart's main pumping chamber (left ventricle). The ventricle stretches and thins (dilates) and can't pump blood as well as a healthy heart can. The term "cardiomyopathy" is a general term that refers to the abnormality of the heart muscle itself.

Dilated cardiomyopathy might not cause symptoms, but for some people it can be life-threatening. A common cause of heart failure — the heart's inability to supply the body with enough blood — dilated cardiomyopathy can also contribute to irregular heartbeats (arrhythmias), blood clots or sudden death.

The condition affects people of all ages, including infants and children, but is most common in men ages 20 to 60.

If you have dilated cardiomyopathy, you're likely to have signs and symptoms of heart failure or arrhythmias caused by your condition. Signs and symptoms include:

  • Fatigue
  • Shortness of breath (dyspnea) when you're active or lying down
  • Reduced ability to exercise
  • Swelling (edema) in your legs, ankles and feet
  • Swelling of your abdomen (ascites)

When to see a doctor

If you're short of breath or have other symptoms of dilated cardiomyopathy, see your doctor. Call 911 or your local emergency number if you feel chest pain that lasts more than a few minutes or have severe difficulty breathing.

If a family member has dilated cardiomyopathy, talk to your doctor about being screened or having family members screened for the condition. Early detection may benefit people with inherited forms of dilated cardiomyopathy who have no apparent signs or symptoms.

The cause of dilated cardiomyopathy often can't be determined (idiopathic). However, numerous factors can cause the left ventricle to dilate and weaken, including:

  • Genetics
  • Congenital heart defects
  • Infections, including those caused by bacteria, viruses, fungi and parasites
  • Drug and alcohol abuse
  • Certain cancer medications
  • Exposure to toxins, such as lead, mercury and cobalt
  • Coronary artery disease or heart attack
  • High blood pressure (hypertension)
  • Diabetes
  • Complications of late-stage pregnancy

Dilated cardiomyopathy most commonly occurs in men, ages 20 to 60. Other risk factors include:

  • High blood pressure (hypertension)
  • Coronary artery disease
  • Damage to the heart muscle from a heart attack
  • Family history of dilated cardiomyopathy
  • Alcoholism
  • Certain chemotherapy drugs and radiation for treating cancer
  • Cocaine use
  • Viral or bacterial infections of the heart muscle
  • Metabolic disorders, such as thyroid disease or diabetes
  • Diseases that can damage the heart, including hemochromatosis and sarcoidosis
  • Obesity
  • Nutritional deficiencies of essential vitamins and minerals, such as selenium
  • Inflammation of heart muscle from immune system disorders, such as lupus
  • Metals and other toxic compounds, such as lead, mercury and arsenic
  • Neuromuscular disorders, such as muscular dystrophy
  • HIV infection

Complications from dilated cardiomyopathy include:

  • Heart failure. Poor blood flow from the left ventricle can lead to heart failure.
  • Heart valve regurgitation. Enlargement of the left ventricle may make it harder for your heart valves to close, causing a backward flow of blood and making your heart pump less effectively.
  • Fluid buildup (edema). Fluid can build up in the lungs, abdomen, legs and feet (edema).
  • Abnormal heart rhythm (arrhythmia). Changes in heart structure and changes in pressure on the heart's chambers can contribute to arrhythmias.
  • Sudden cardiac arrest. Dilated cardiomyopathy can cause your heart to suddenly stop beating.
  • Blood clots (emboli). Pooling of blood (stasis) in the left ventricle can lead to blood clots, which may enter the bloodstream, cut off the blood supply to vital organs, and cause stroke, heart attack or damage to other organs. Arrythmias can also cause blood clots.

If you think you may have dilated cardiomyopathy or are worried about your risk because of a family history, make an appointment with your family doctor. Eventually, you may be referred to a heart specialist (cardiologist).

Here's information to help you get ready for your appointment.

What you can do

  • Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.
  • Write down symptoms you're experiencing, including any that may seem unrelated to dilated cardiomyopathy.
  • Write down key personal information, including major stresses or recent life changes and a family history of heart disease, stroke, high blood pressure or diabetes.
  • List all medications, vitamins and supplements you're taking.
  • Take a family member or friend along, if possible. Someone who accompanies you may remember something that you missed or forgot.
  • Be prepared to discuss your diet and exercise habits. If you don't already follow a diet or exercise routine, talk to your doctor about how to get started.
  • Write down questions to ask your doctor.

Preparing a list of questions will help you make the most of your time with your doctor. For dilated cardiomyopathy, some basic questions include:

  • What is likely causing my symptoms or condition?
  • What are other possible causes?
  • What tests will I need?
  • What's the best treatment?
  • What are the alternatives to the primary approach you're suggesting?
  • How should I change my diet?
  • What's an appropriate level of physical activity?
  • How often should I be screened?
  • Should I tell my family to be screened for dilated cardiomyopathy?
  • I have other health conditions. How can I best manage them together?
  • Are there restrictions that I need to follow?
  • Should I see a specialist?
  • Is there a generic alternative to the medicine you're prescribing?
  • Are there brochures or other printed materials I can take with me? What websites do you recommend?

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

  • When did your symptoms begin?
  • Have your symptoms been continuous or occasional?
  • How severe are your symptoms?
  • What, if anything, seems to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?
  • Do any of your blood relatives have dilated cardiomyopathy or other types of heart disease?

Your doctor will take a personal and family medical history, do a physical exam using a stethoscope to listen to your heart and lungs, and order tests. He or she may refer you to a heart specialist (cardiologist) for testing.

Tests your doctor might order include:

  • Blood tests. These tests give your doctor information about your heart. They also may reveal if you have an infection, a metabolic disorder or toxins in your blood that can cause dilated cardiomyopathy.
  • Chest X-ray. Your doctor may order a chest X-ray to check your heart and lungs for abnormalities in the heart's structure and size and for fluid in or around your lungs.
  • Electrocardiogram (ECG). An electrocardiogram — also called an ECG or EKG — records electrical signals as they travel through your heart. Your doctor can look for patterns that show abnormal heart rhythm or problems with the left ventricle. Your doctor may ask you to wear a portable ECG device known as a Holter monitor to record your heart rhythm for a day or two.
  • Echocardiogram. This primary tool for diagnosing dilated cardiomyopathy uses sound waves to produce images of the heart, allowing your doctor to see whether your left ventricle is enlarged. This test can also reveal how much blood is ejected from the heart with each beat and whether blood is flowing in the right direction.
  • Exercise stress test. Your doctor may have you perform an exercise test, either walking on a treadmill or riding a stationary bike. Electrodes attached to you during the test help your doctor measure your heart rate and oxygen use.

    This type of test can show the severity of problems caused by dilated cardiomyopathy. If you're unable to exercise, you may be given medication to create the stress.

  • CT or MRI scan. In some situations, your doctor might order one of these tests to check the size and function of your heart's pumping chambers.
  • Cardiac catheterization. For this invasive procedure, a long, narrow tube is threaded through a blood vessel in your arm, groin or neck into the heart. The test enables your doctor to see your coronary arteries on X-ray, measure pressure in your heart and collect a sample of muscle tissue to check for damage that indicates dilated cardiomyopathy.

    This procedure may involve having a dye injected into your coronary arteries to help your doctor study your coronary arteries (coronary angiography).

  • Genetic screening or counseling. If your doctor can't identify the cause of dilated cardiomyopathy, he or she may suggest screening of other family members to see if the disease is inherited in your family.

If you have dilated cardiomyopathy, your doctor might recommend treatment for the underlying cause, if known, and to improve blood flow and prevent further heart damage.

Medications

Doctors usually treat dilated cardiomyopathy with a combination of medications. Depending on your symptoms, you might need two or more of these drugs.

Drugs that have proved useful in the treatment of heart failure and dilated cardiomyopathy include:

  • Angiotensin-converting enzyme (ACE) inhibitors. ACE inhibitors are a type of drug that widens or dilates blood vessels (vasodilator) to lower blood pressure, improve blood flow and decrease the heart's workload. ACE inhibitors may improve heart function.

    Side effects include low blood pressure, low white blood cell count, and kidney or liver problems.

  • Angiotensin II receptor blockers. These drugs have many of the beneficial effects of ACE inhibitors and may be an alternative for people who can't tolerate ACE inhibitors. Side effects include diarrhea, muscle cramps and dizziness.
  • Beta blockers. A beta blocker slows your heart rate, reduces blood pressure and prevents some of the harmful effects of stress hormones, substances produced by your body that can worsen heart failure and trigger abnormal heart rhythms.

    Beta blockers may reduce signs and symptoms of heart failure and improve heart function. Side effects include dizziness and low blood pressure.

  • Diuretics. Often called water pills, diuretics remove excess fluid and salt from your body. The drugs also decrease fluid in your lungs, so you can breathe more easily.
  • Digoxin. This drug, also known as digitalis, strengthens your heart muscle contractions. It also tends to slow the heartbeat. Digoxin may reduce heart failure symptoms and improve your ability to be active.
  • Blood-thinning medications. Your doctor may prescribe drugs, including aspirin or warfarin (Coumadin), to help prevent blood clots. Side effects include excessive bruising or bleeding.

Devices

Implantable devices used to treat dilated cardiomyopathy include:

  • Biventricular pacemakers, which use electrical impulses to coordinate the actions of the left and right ventricle.
  • Implantable cardioverter-defibrillators (ICDs), which monitor heart rhythm and deliver electrical shocks when needed to control abnormal, rapid heartbeats, including those that cause the heart to stop. They can also function as pacemakers.
  • Heart pumps (left ventricular assist devices, or LVADs). These mechanical devices are implanted into the abdomen or chest and attached to a weakened heart to help it pump. They usually are considered after less invasive approaches are unsuccessful.

Heart transplant

You may be a candidate for a heart transplant if medications and other treatments are no longer effective.

If you have dilated cardiomyopathy, these self-care strategies may help:

  • Exercise. Talk to your doctor about what activities would be safe and beneficial for you. In general, competitive sports aren't recommended because they can increase the risk of the heart stopping and causing sudden death.
  • Quit smoking. Your doctor can give you advice on what methods can help you stop.
  • Don't use illegal drugs or drink alcohol excessively. Using cocaine or other illegal drugs can strain your heart. Before you drink alcohol, ask your doctor for advice.
  • Maintain a healthy weight. Extra weight makes the heart work harder. Lose weight if you're overweight or obese.
  • Eat a heart-healthy diet. Eating whole grains and a variety of fruits and vegetables, and limiting salt, added sugar, and cholesterol and saturated and trans fats is good for your heart. Ask your doctor for a referral to a dietitian if you need help planning your diet.

Healthy lifestyle habits can help you prevent or minimize the effects of dilated cardiomyopathy.

  • Don't smoke.
  • Don't drink alcohol, or drink in moderation.
  • Don't use cocaine or other illegal drugs.
  • Eat a healthy diet.
  • Maintain a healthy weight.
  • Follow an exercise regimen recommended by your doctor.
  • Get enough sleep and rest.
Aug. 19, 2014