What is Cardiomyopathy?
Cardiomyopathy is a serious disease in which the heart muscle becomes inflamed and
doesn’t work as well as it should. There may be multiple causes including viral infections.

Cardiomyopathy can be classified as primary or secondary. Primary cardiomyopathy can’t be attributed to a specific cause, such as hypertension, heart valve disease, artery diseases or congenital heart defects. Secondary cardiomyopathy is due to specific causes and is often associated with diseases involving other organs as well as the heart. There are three principal types of cardiomyopathy — dilated, hypertrophic and restrictive.

What is dilated (congestive) cardiomyopathy?
This is the most common form. The heart cavity is enlarged and stretched (cardiac dilation). The heart is weak and doesn’t pump normally, and most patients develop congestive heart failure. Arrhythmias and disturbances in the heart’s electrical conduction also may occur.

Since blood flows more slowly through an enlarged heart, blood clots easily form. A blood clot is also called a thrombus. A clot that breaks free, circulates in the bloodstream and blocks a small blood vessel is called an embolus. It can cause life-threatening problems in many parts of the body.

• Clots that stick to the inner lining of the heart are called mural thrombi.
• If the clot breaks off in the right ventricle, it can be carried into the pulmonary circulation in the lung, forming pulmonary emboli.
• Blood clots formed in the heart’s left side may be dislodged and carried into the body’s circulation. They can form cerebral emboli in the brain, renal emboli in the
  kidney, peripheral emboli in the arms or legs or even coronary artery emboli in the heart.

A condition known as Barth syndrome, a rare and relatively unknown genetically linked heart disease, can cause dilated cardiomyopathy. This syndrome affects male children, usually during their first year of life, but it can be diagnosed later. In these young patients the heart condition is often associated with changes in the skeletal muscles, short stature and an increased likelihood of bacterial infections. They also have a condition known as neutropenia, which is a reduced number of white blood cells (neutrophils). There are clinical signs of the cardiomyopathy in the newborn child or within the first months of life. These children also have metabolic and mitochondrial abnormalities.






How is dilated or congestive cardiomyopathy treated?
A person with cardiomyopathy may suffer an embolus before any other symptom of cardiomyopathy appears, and anti-clotting (anticoagulant) drug therapy may be needed. Arrhythmias may require antiarrhythmic drugs. More rarely, “heart block” may develop, requiring an artificial pacemaker. Therapy for dilated cardiomyopathy is
sometimes disappointing. If the person is young and otherwise healthy, and if the disease gets worse and worse, a heart transplant may be considered.

When cardiomyopathy results in marked heart dilation, the leaflets of the mitral and tricuspid valves may not be able to close properly, resulting in murmurs. Blood pressure may rise because of increased sympathetic nerve activity. These nerves also can cause arteries to narrow. This mimics high blood pressure. That’s why some people have high blood pressure readings. Because the level of blood pressure determines the heart’s workload and oxygen needs, one treatment approach is to use vasodilators (drugs that “relax” the arteries). They lower blood pressure and thus the left ventricle’s workload.





What is hypertrophic cardiomyopathy?
In this condition, the muscle mass of the left ventricle enlarges or “hypertrophies.” In one form of the disease, the wall between the two ventricles (septum) becomes enlarged and obstructs the blood flow from the left ventricle. Besides obstructing blood flow, the thickened wall sometimes distorts one leaflet of the mitral valve, causing it to leak.

The syndrome is known as hypertrophic obstructive cardiomyopathy (HOCM) or asymmetric septal hypertrophy (ASH). It’s also called idiopathic hypertrophic subaortic stenosis (IHSS). In the other form of the disease, nonobstructive hypertrophic cardiomyopathy, the enlarged muscle doesn’t obstruct blood flow.

In over half the cases, the disease is hereditary. Close blood relatives (parents, children or siblings) of such persons often have enlarged septums, although they may have no symptoms.


The symptoms of hypertrophic cardiomyopathy include shortness of breath on exertion, dizziness, fainting and angina pectoris (chest pain or discomfort caused by reduced blood supply to the heart muscle). Some people have cardiac arrhythmias, abnormal heart rhythms that in some cases can lead to sudden death. The obstruction to blood flow from the left ventricle increases the ventricle’s work, and a heart murmur may be heard.






How is hypertrophic cardiomyopathy treated?
A drug (a beta blocker or a calcium channel blocker) is the usual treatment. If a person has an arrhythmia, an antiarrhythmic drug may alsobe used. If the drug treatment fails, sometimes surgery is done on the obstructive form of hypertrophic cardiomyopathy.

Alcohol ablation is another nonsurgical treatment being developed for hypertrophic obstructive cardiomyopathy. It involves injecting alcohol down a small branch of one of the heart arteries to the extra heart muscle. This destroys the extra heart muscle without having to cut it out surgically.

People undergoing this procedure usually suffer chest pain during the alcohol injection.
The alcohol also can disrupt normal heart rhythms and require the insertion of a pacemaker. Alcohol ablation is a relatively new procedure being done at only a few specialized centers. However, it’s too soon to know whether this treatment will result in long-term benefit. It’s still considered experimental.






What is restrictive cardiomyopathy?
The myocardium of the ventricles becomes excessively “rigid,” so it’s harder for the ventricles to fill with blood between heartbeats. A person with restrictive cardiomyopathy often complains of being tired, may have swollen hands and feet, and may have difficulty breathing on exertion. This type of cardiomyopathy is usually due to another disease process.