What is this condition?

Dilated cardiomyopathy is caused by extensively damaged heart muscle fibers. This disorder interferes with the heart’s metabolism and greatly enlarges all four chambers of the heart, giving the heart a globular shape and causing it to contract poorly .

Dilated cardiomyopathy leads to intractable congestive heart failure, irregular heart rhythm, and emboli (blood clots or other material that is carried in the bloodstream). Because this disease usually isn’t diagnosed until it’s in the advanced stages, the prognosis is generally poor.

What causes it?

The cause of most cardiomyopathies is unknown. Dilated cardiomyopathy may occur as a primary heart disease or it may result from viruses, endocrine and electrolyte disorders, or nutritional deficiencies. Other causes include muscle disorders (myasthenia gravis, progressive muscular dystrophy, myotonic dystrophy), infiltrative disorders (hemochromatosis, amyloidosis, sarcoidosis), and some­times pregnancy.

Cardiomyopathy may also be a complication of alcoholism. The condition may improve somewhat with abstinence but recurs when the person resumes drinking.

What are its symptoms?

In dilated cardiomyopathy, the heart ejects blood less efficiently than normal. Consequently, a large volume of blood remains in the left ventricle after its contraction, causing shortness of breath, fatigue, an irritating dry cough at night, swelling, liver engorgement, and swelling of the neck veins.

How is it diagnosed?

No single test confirms dilated cardiomyopathy. Diagnosis requires elimination of other possible causes of congestive heart failure and irregular heart rhythms. Tests include the following:

• Electrocardiography and angiography rule out ischemic heart disease; the electrocardiogram may also show an enlarged heart .

• Chest X-ray demonstrates an enlarged heart, lung congestion, or pleural effusion.

How is it treated?

Therapeutic goals include correcting the underlying causes and improving the heart’s pumping ability with drugs, oxygen, and a sodium-restricted diet. Other options may include bed rest and steroids.

When these treatments fail, therapy may require a heart transplant for carefully selected people. Another option for selected individuals is cardiomyoplasty, a surgical procedure in which the latissimus dorsi muscle is wrapped around the ventricles. This helps the ventricle to effectively pump blood. A cardiomyostimulator delivers bursts of electrical impulses to contract the muscle