Dilated cardiomyopathy

Definition

Dilated cardiomyopathy is a condition in which the heart becomes weakened and enlarged. As a result, the heart cannot pump enough blood to the rest of the body.

There are several different types of cardiomyopathy. Dilated cardiomyopathy is the most common form.

Alternative Names

Cardiomyopathy - dilated

Causes, incidence, and risk factors

Heart disease (which is caused by a narrowing of the arteries) and poorly controlled high blood pressure are the most common causes of dilated cardiomyopathy. These problems lead to a weakened and enlarged heart muscle.

There are many other causes of dilated cardiomyopathy, including:

• Alcohol or cocaine abuse, or medicines that can be toxic to the heart (such as drugs used to treat cancer)
• Abnormal heart rhythms in which the heart beats very fast for a long period of time
• Autoimmune illnesses, when the immune system attacks and destroys healthy body tissue by mistake 
• Conditions that run in families
• Infections that involve the heart muscle
• Heart valves that are either too narrow or too leaky (regurgitant)
• Trace elements, such as lead, arsenic, or mercury

This condition can affect anyone at any age. However, it is most common in adult men.

Symptoms

Symptoms of heart failure are most common. Usually, they develop slowly over time. However, sometimes symptoms start very suddenly and are severe.

Common symptoms are:

• Chest pain or pressure (more likely when you exercise)
• Cough
• Fatigue, weakness, faintness
• Irregular or rapid pulse
• Loss of appetite
• Shortness of breath with activity or after lying down (or being asleep) for a while
• Swelling of feet and ankles (in adults)

Signs and tests

During the exam the health care provider may find:.

• The heart is enlarged
• Lung crackles (a sign of fluid buildup), heart murmur, or other abnormal sounds
• The liver may be enlarged
• Neck veins may be bulging

A number of laboratory tests may be done to determine the cause:

• Antinuclear antibody (ANA), erythrocyte sedimentation rate (ESR), and other tests to diagnose autoimmune illnesses
• Antibody test to identify infections such as Lyme disease and HIV
• Iron tests on the blood
• Serum TSH and T4 test to identify thyroid problems
• Tests for amyloidosis

Heart enlargement or other problems with the structure and function of the heart (such as weak squeezing) may show up on these tests:

• Echocardiogram (ultrasound of the heart)
• Cardiac stress tests
• Chest x-ray
• Coronary angiogram to look at blood flow to the heart 
• CT scan of the heart
• MRI of the heart
• Nuclear heart scan (MUGA, RNV)

Heart biopsy, in which a small piece of heart muscle is removed, may be needed depending on the cause. However, this is uncommon.

Treatment

Knowing your body and the symptoms that your heart failure is getting worse will help you stay healthier and out of the hospital. At home, watch for changes in your symptoms, heart rate, pulse, blood pressure, and weight.

Limiting how much you drink and how much salt (sodium) you eat can help prevent or reduce these symptoms.

Most people who have heart failure need to take medicines. Some medicines treat your symptoms. Others may help prevent your heart failure from becoming worse or may prevent other heart problems.

Procedures and surgeries you may need are:

• A pacemaker to help treat slow heart rates or help your heart contract in a more coordinated fashion
• A defibrillator that recognizes life-threatening heart rhythms and sends an electrical pulse to stop them
• Heart bypass (CABG) surgery or angioplasty to improve blood flow to the damaged or weakened heart muscle
• Valve replacement or repair

For advanced cardiomyopathy:

• A heart transplant may be recommended for patients who have failed all the standard treatments and still have very severe symptoms.
• Placement of a left ventricular assist device or artificial heart may be considered.

Chronic heart failure becomes worse over time. Many people who have heart failure will die from the condition. Thinking about the type of care you may want at the end of life and discussing these issues with loved ones and your health care provider is important.

Support Groups

Expectations (prognosis)

Heart failure is most often a chronic illness, which may get worse over time. Some people develop severe heart failure, in which medicines, other treatments, and surgery no longer help. Many people are at risk for deadly heart rhythms, and may need medicines or a defibrillator.

Complications

Calling your health care provider

Call your health care provider if you have symptoms of cardiomyopathy.

If chest pain, palpitations, or faintness develop seek emergency medical treatment immediately.

Prevention

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References

Hare JM. The dilated, restrictive, and infiltrative cardiomyopathies. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 68.