A B C D E F G H I J K L M N O P R S T U V W

CARDIOMYOPATHY

What is Cardiomyopathy?

Cardiomyopathy is a disease of the heart muscle, particularly of the left ventricle – the main pumping chamber. There are four different types. The commonest, called dilated cardiomyopathy, causes the heart to dilate or enlarge. Hypertrophic cardiomyopathy, the next commonest, causes the heart muscle to become thick and bulky (hypertrophy means thickening). In some patients this may obtruct the outflow of blood from the left ventricle. The other two types of cardiomyopathy are rare: one is called restrictive because the heart's relaxation is interfered with (or restricted). The fourth is called Arrythmogenic Right Ventricular Dysplasia (ARVD) in which the problems are those of heart rhythm. In the first three types of cardiomyopathy, the heart's pumping function is impaired. Symptoms may not happen immediately because the heart can continue to function reasonably well despite being abnormal. Eventually, however, the blood pressure starts to fall, and the body tries to compensate. For instance, the kidneys can retain fluid in an attempt to keep the blood pressure up. Unfortunately this mechanism tends to over-correct, so that too much fluid is retained. This excess fluid leaks into the tissues causing swelling of the feet and ankles. It also leaks into the lungs and causes breathlessness. This is called heart failure and occurs particularly in dilated cardiomyopathy. In hypertrophic cardiomyopathy there may be a tendency to faint and have blackouts. This is because the excess muscle actually blocks the flow of blood out of the heart. The obstruction and the overdevelopment of heart muscle may lead to angina. This is a particular type of chest pain usually occurring with physical effort. The pain is due to the fact that not enough blood can be conducted through the coronary arteries to supply the thickened heart muscle.

How and why does Cardiomyopathy occur?

Dilated cardiomyopathy may occur with some forms of gland (hormone) abnormalities. The commonest are an overactive thyroid or adrenal gland disorders. It may also happen with infections of the heart, particularly due to a virus. Toxins (poisons) may also damage the heart muscle leading to cardiomyopathy. The commonest toxin is alcohol although it happens only when taken in great excess; in moderation, alcohol does not cause heart problems. Occasionally cardiomyopathy may occur after childbirth or with other rare diseases called auto?immune disease. Mostly, cardiomyopathies occur for reasons that cannot be pinned down. Some forms, particularly the hypertrophic type, seem to be familial: they are to some extent inherited and may occur in several generations of the same family.

What does treatment/management of Cardiomyopathy involve?

DIAGNOSIS Tests are needed to see if there is a specific cause such as a toxin or a gland disorder. This may involve blood tests. Other tests are needed to exclude other heart conditions, particularly coronary artery disease. This is quite common and quite treatable. A chest x?ray and an electrocardiogram (ECG) are standard tests, but echocardiography is perhaps the most useful. This uses high frequency sound (ultrasound) transmitted from an instrument (called a transducer) placed on the chest. Like ordinary sound waves, ultrasound is reflected off the structures inside the chest back to the transducer where the sound is converted into electrical impulses which are displayed as a TV picture. This allows the structure and function of the heart to be analysed. Sometimes cardiac catheterization is required, especially if coronary artery disease is suspected. This involves passing a fine tube into the heart from an artery in the arm or groin. It allows the heart specialist to find out rather more about how the heart is working.

TREATMENT If there is a gland problem or an infection, specific treatment for that problem may be needed. Treatment of dilated cardiomyopathy is necessary only if the symptoms of heart failure develop. Treatments include diuretics, which get rid of extra body fluid, or drugs to lower the blood pressure if it happens to be too high (high blood pressure puts an extra load on a heart already affected by another disorder) . Occasionally there is a tendency for blood clots to form inside the heart. If so, drugs to combat this (anticoagulants) are prescribed. Sometimes pain (angina) is a problem in hypertrophic cardiomyopathy. Medicines are required for that too. These are similar to those used for treating angina caused by coronary artery disease such as beta-blockers. Sometimes medication to control the heart rhythm is needed. In hypertrophic cardiomyopathy, heart rhythm abnormalities may be particularly important. Twenty?four hour tape recordings of the ECG may be needed to identify such rhythm disorders. In this disease, cardiac catheter techniques can be used to obliterate part of the heart muscle which causes the obstruction to blood flow. Cardiac pacemakers may also be used sometimes. By altering the timing of atrial (receiving chamber) and ventricle (pumping chamber) contraction, the obstruction to blood flow may be reduced. Rarely, surgery can also be undertaken for hypertrophic cardiomyopathy. These, invasive treatments are, of course, only considered if the symptoms are severe and do not respond to medical treatment.

What to watch out for during treatment of Cardiomyopathy?

The symptoms of heart failure, due to dilated cardiomyopathy, may appear or get worse. Treatment may need to be started or increased. Heart failure symptoms may develop with hypertrophic cardiomyopathy also. More commonly it is anginal pain, dizziness and blackouts that are the problem here. Medical help must be sought for these problems. It is essential not to stop any drugs without first checking with the doctor.

What would happen if Cardiomyopathy was not treated?

As with many heart conditions that cause the symptoms of heart failure, they would probably be worse if they were not treated and could become fatal. Treatment is not usually needed, if there are no symptoms.

What is involved for family & friends?

Genetic counselling may be sensible, particularly with hypertrophic cardiomyopathy because it is inherited. This involves advice about the chances of it affecting children and other close relatives. An understanding of the problems by the family is always useful. Sometimes there may be a need to take less exercise. It is useful for the family to know about this.