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Dilated (Congestive) Cardiomyopathy

The most common type of nonischemic cardiomyopathy is the dilated form. This occurs when disease affected muscle fibers lead to enlargement or dilation of one or more chambers of the heart (the heart muscles are actually stretched and weakened). The dilation reduces the heart's pumping ability.

Characteristics of Dilated Cardiomyopathy

Highest incidence is in middle-aged men.
It can occur at any age including childhood.
Most cases are termed idiopathic (i.e. a specific cause is never identified).
The following factors have been linked to the disease: chronic excessive alcohol consumption, complications during child birth, viral infections that lead to inflammation of the heart muscle (called myocarditis), toxins, and some drugs used to treat cancer.

Symptoms of Dilated Cardiomyopathy

Dilated cardiomyopathy can be present for several years without symptoms. It gradually enlarges the heart and weakens it pumping power. This is called "heart failure" and is the hallmark of dilated cardiomyopathy.
Heart failure symptoms include: fatigue, weakness, shortness of breath that may be severe and increasing with exertion or lying down, swelling of legs and feet.
In advanced stages, dilated cardiomyopathy may cause pain in chest or abdomen.
Some patients develop irregular heartbeats, which can be serious and even life threatening.

Diagnosis of Dilated Cardiomyopathy

Once symptoms appear, a physical exam and the patient's medical history can lead to the diagnosis. The following tests can differentiate dilated cardiomyopathy from other causes of heart failure:

Chest x-ray, which determines if heart is enlarged.
An EKG, which determines if any irregular heartbeats are present.
Echocardiogram, which uses sound waves to produce detailed pictures of the heart.

In some cases, more "invasive" tests may be indicated. These include:

Radionuclide ventriculogram This involves injecting low dose radioactive material into a vein, through which it flows to the heart. Pictures are generated by a camera to show how well the heart is functioning.

Cardiac catheterization This involves placing a thin plastic tube through a blood vessel until it reaches the heart. A dye is injected and x-rays taken to assess the heart's structure and function (see this link for an excellent discussion and diagram of cardiac catheterization http://www.vh.org/Patients/IHB/IntMed/Cardio/Cath/Intro.html)

Treatment of Dilated Cardiomyopathy

Unfortunately, by the time of diagnosis, the disease has often reached an advanced stage and heart failure has occurred. Only 50% of patients with dilated cardiomyopathy live 5 years once heart failure is diagnosed. About 25% live 10 years after such a diagnosis. No cure exists.

Four types of medications are used to manage the symptoms:

Diuretics, which reduce excess fluid in the body.
Vasodilators, which reduce blood pressure and reduce effort needed by heart to pump the blood through the body
Digitalis, which improve the pumping action of the heart and regulates heart rate.
Calcium blockers or beta-blockers, which regulate heart rate.

Heart transplantation may be needed. The patient's heart is replaced with a donor heart. Heart transplantation improves survival. 75% of patients live 5 years after transplantation. Due to a scarcity of donor hearts, only about 2,000 patients receive transplantation.

Hypertrophic Cardiomyopathy (IHSS)

The second most common form of heart muscle disease is hypertrophic cardiomyopathy. Physicians sometimes call it by other names: idiopathic hypertrophic subaortic stenosis (IHSS), asymmetrical septal hypertrophy (ASH), or hypertrophic obstructive cardiomyopathy (HOCM).

In hypertrophic cardiomyopathy, the growth and arrangement of muscle fibers are abnormal, leading to thickened heart walls. The greatest thickening tends to occur in the left ventricle (the heart's main pumping chamber). Thickening reduces the size of the pumping chamber and obstructs blood flow. Eventually this affects the pumping action of the heart.

Characteristics of Hypertrophic Cardiomyopathy

It is a rare disease found in less than 2% of the U.S. population.
It can occur in people of all ages, including children.
It can affect both men and women.
Most cases have a genetic connection, although sometimes there is no clear cause.

Symptoms of Hypertrophic Cardiomyopathy

Many patients have no symptoms.
The most common symptoms are breathlessness and chest discomfort.
Other signs are fainting during physical activity, strong rapid heartbeats that feel like a pounding in the chest and fatigue with physical exertion.
In some cases, the first and only symptom is sudden death, caused by a chaotic heartbeat.

Diagnosis of Hypertrophic Cardiomyopathy

The first physical discovery of hypertrophic cardiomyopathy may be from a murmur heard by a health care provider. This discovery will prompt an echocardiogram. An echocardiogram is one of the best tools for diagnosing hypertrophic cardiomyopathy. It uses sound waves to detect the extent of muscle-wall thickening and to assess the status of the heart's functioning. Other tests used in the diagnosis include:

Chest x-ray, which determines if heart is enlarged.
EKG, which determines if any irregular heartbeats are present.

In some cases, more "invasive" tests may be indicated. These include:

Radionuclide ventriculogram This involves injecting low dose radioactive material into a vein, through which it flows to the heart. Pictures are generated by a camera to show how well the heart is functioning.

Cardiac catheterization This involves placing a thin plastic tube through a blood vessel until it reaches the heart. A dye is injected and x-rays taken to assess the heart's structure and function.

Treatment of Hypertrophic Cardiomyopathy

Lifestyle changes Patients with serious electrical and blood flow abnormalities of the heart must be less physically active.

Medications Various drugs are used to treat the disease which include:

Diuretics, which reduce excess fluid in the body.
Vasodilators, which reduce blood pressure and reduce effort needed by heart to pump the blood through the body
Digitalis, which improve the pumping action of the heart and regulates heart rate.
Calcium blockers or beta-blockers, which regulate heart rate.

However, drugs do not work in all cases or may cause adverse side effects. Other treatments, such as a pacemaker or surgery, may be needed.

Pacemakers These change the pattern and decrease the force of the heart's contractions. The pacemaker can reduce the degree of obstruction and so relieve symptoms. Some patients who have a pacemaker inserted feel no relief and go on to have heart surgery.

Surgery This usually calls for removal of part of the thickened septum (the muscle wall separating the chambers) that is blocking the blood flow. Surgery to remove the thickening eases symptoms in about 70 percent of patients but results in death in about 1 to 3 percent of patients.

Hypertrophic cardiomyopathy patients also are at risk of sudden death. About 2 to 3 percent die each year because the heart suddenly stops beating. This cardiac arrest is brought on by an abnormal heartbeat. Over 10 years, the risk of sudden death can be 20 percent or more.

Restrictive Cardiomyopathy

Restrictive cardiomyopathy is rare in the U.S. and most other industrial nations. In this disease, the walls of the ventricles stiffen and lose their flexibility due to infiltration by abnormal tissue. As a result, the heart cannot fill adequately with blood and eventually loses its ability to pump properly.

Restrictive cardiomyopathy typically results from another disease occurring elsewhere in the body. In the U.S., restrictive cardiomyopathy is most commonly related to the following: amyloidosis, sarcoidosis and hemochromatosis.

Symptoms of Restrictive Cardiomyopathy

Typical signs of the condition include symptoms of congestive heart failure: weakness, fatigue and breathlessness.
Swelling of the legs, caused by fluid retention, occurs in a significant number of patients.
Other signs include nausea, bloating, and poor appetite, probably because of the retention of fluid around the liver, stomach and intestines.

Diagnosis of Restrictive Cardiomyopathy

A physician may suspect restrictive cardiomyopathy based on a patient's symptoms and the presence of another disease. Although symptoms of congestive heart failure may predominate, the size of the heart remains relatively small, unlike other cardiomyopathies.

Diagnostic information comes from an echocardiogram or other imaging studies that provide pictures of the heart. These include magnetic resonance imaging (MRI), and computed tomography (CT Scan).

A definite diagnosis usually requires cardiac catheterization studies or biopsy, in which a tiny piece of tissue (including heart muscle) is removed for laboratory analysis.

Treatment of Restrictive Cardiomyopathy

Restrictive cardiomyopathy has no specific treatment. The underlying disease that leads to the heart problem also may not be treatable.

In general, the use of traditional heart drugs has been limited in this cardiomyopathy, although diuretics may help control fluid accumulation.

In rare cases, surgery is sometime used to try to improve blood flow into the heart.

The condition is similar to dilated cardiomyopathy and tends to worsen with time. Only about 30 percent of patients survive more than 5 years after diagnosis.