Cardiomyopathy is a weakening of the heart muscle or a change in heart muscle structure. It is often associated with inadequate heart pumping or other heart function problems.
Cardiomyopathy (KAR-de-o-mi-OP-ah-thee) refers to diseases of the heart muscle. These diseases have many causes, signs and symptoms, and treatments.
In cardiomyopathy, the heart muscle becomes enlarged, thick, or rigid. In rare cases, the muscle tissue in the heart is replaced with scar tissue.
As cardiomyopathy worsens, the heart becomes weaker. It's less able to pump blood through the body and maintain a normal electrical rhythm. This can lead to failure or irregular heartbeats called arrhythmias (ah-RITH-me-ahs). In turn, heart failure can cause fluid to build up in the lungs, ankles, feet, legs, or abdomen.
The weakening of the heart also can cause other complications, such as heart valve problems.
The main types of cardiomyopathy are:
- Dilated cardiomyopathy
- Hypertrophic (hi-per-TROF-ik) cardiomyopathy
- Restrictive cardiomyopathy
- Arrhythmogenic (ah-rith-mo-JEN-ik) right ventricular dysplasia (dis-PLA-ze-ah)
Other types of cardiomyopathy sometimes are referred to as "unclassified cardiomyopathy."
Cardiomyopathy can be acquired or inherited. "Acquired" means you aren't born with the disease, but you develop it due to another disease, condition, or factor. "Inherited" means your parents passed the gene for the disease on to you. Many times, the cause of cardiomyopathy isn't known.
Cardiomyopathy can affect people of all ages. However, people in certain age groups are more likely to have certain types of cardiomyopathy. This article focuses on cardiomyopathy in adults.
Some people who have cardiomyopathy have no signs or symptoms and need no treatment. For other people, the disease develops quickly, symptoms are severe, and serious complications occur.
Treatments for cardiomyopathy include lifestyle changes, medicines, surgery, implanted devices to correct arrhythmias, and a nonsurgical procedure. These treatments can control symptoms, reduce complications, and stop the disease from getting worse.>
Alternative Names of Cardiomyopathy are: Cardiomyopathy - peripartum.
Complications of Cardiomyopathy
- Cardiac arrhythmias (can be deadly)
- Congestive heart failure
- Pulmonary emboli (blood clots in the lungs)
Causes of Cardiomyopathy
Most of the time, the cause of the cardiomyopathy is unknown. In some people, however, doctors are able to identify some contributing factors. Possible causes of cardiomyopathy include:
- Long-term high blood pressure
- Heart valve problems
- Heart tissue damage from a previous heart attack
- Chronic rapid heart rate
- Metabolic disorders, such as thyroid disease or diabetes
- Nutritional deficiencies of essential vitamins or minerals, such as thiamin (vitamin B-1), selenium, calcium and magnesium
- Excessive use of alcohol over many years
- Abuse of cocaine or antidepressant medications, such as tricyclic antidepressants
- Use of some chemotherapy drugs to treat cancer
- Certain viral infections, which may injure the heart and trigger cardiomyopathy
- Iron buildup in your heart muscle (hemochromatosis)
The three types of cardiomyopathy are:
Dilated cardiomyopathy : This is the most common type of cardiomyopathy. In this disorder, your heart's main pumping chamber - the left ventricle - becomes enlarged (dilated), its pumping ability becomes less forceful, and blood doesn't flow as easily through the heart. Although this type can affect people of all ages, it occurs most often in middle-aged people and is more likely to affect men. Some people with dilated cardiomyopathy have a family history of the condition.
Hypertrophic cardiomyopathy : This type involves abnormal growth or thickening of your heart muscle, particularly affecting the muscle of your heart's main pumping chamber. As thickening occurs, the heart tends to stiffen and the size of the pumping chamber may shrink, interfering with your heart's ability to deliver blood to your body. Hypertrophic cardiomyopathy can develop at any age, but the condition tends to be more severe if it becomes apparent during childhood. Most affected people have a family history of the disease, and some genetic mutations have been linked to hypertrophic cardiomyopathy.
Restrictive cardiomyopathy : The heart muscle in people with restrictive cardiomyopathy becomes rigid and less elastic, meaning the heart can't properly expand and fill with blood between heartbeats. While restrictive cardiomyopathy can occur at any age, it most often tends to affect older people. It's the least common type of cardiomyopathy and can occur for no known reason (idiopathic). The condition may also be caused by diseases elsewhere in the body that affect the heart.
Signs & Symptoms of Cardiomyopathy
Some people who develop cardiomyopathy have no signs and symptoms during the early stages of the disease. But as the condition advances, signs and symptoms usually appear. Cardiomyopathy symptoms may include:
- Breathlessness with exertion or even at rest
- Swelling of the legs, ankles and feet
- Bloating of the abdomen due to fluid buildup
- Irregular heartbeats that feel rapid, pounding or fluttering
- Dizziness, lightheadedness and fainting
No matter what type of cardiomyopathy you have, signs and symptoms tend to get worse unless treated. In certain people, this worsening happens quickly, while in others, cardiomyopathy may not worsen for a long time.
Diagnosis of Cardiomyopathy
Your doctor will conduct a physical examination, take a personal and family medical history, and ask when your symptoms occur - for example, whether exercise brings on your symptoms. If your doctor thinks you have cardiomyopathy, you may need to undergo several tests to confirm the diagnosis. These tests may include:
Chest X-ray : An image of your heart will show whether it's enlarged.
Echocardiogram : An echocardiogram uses sound waves to produce images of the heart. Your doctor can use these images to examine the size of your heart and its motions as it beats.
Electrocardiogram (ECG) : In this noninvasive test, electrode patches are attached to your skin to measure electrical impulses from your heart. An ECG can show disturbances in the electrical activity of your heart, which can detect abnormal heart rhythms and areas of injury.
Cardiac catheterization and biopsy : In this procedure, a thin tube (catheter) is inserted in your groin and threaded through your blood vessels to your heart, where a small sample (biopsy) of your heart can be extracted for analysis in the laboratory. Pressure within the chambers of your heart can be measured to see how forcefully blood pumps through your heart. Pictures of the arteries of the heart can be taken during the procedure (coronary angiogram) to ensure that you do not have any blockage.
Cardiac magnetic resonance imaging (MRI) : Cardiac MRI is an imaging technique that uses magnetic fields and radio waves to create images of your heart. Cardiac MRI is often used in addition to echocardiography, particularly if the images from your echocardiogram aren't helpful in making a diagnosis.
Blood tests : One blood test can measure B-type natriuretic peptide (BNP), a protein produced in your heart. Your blood level of BNP rises when your heart is subjected to the stress of heart failure, a common complication of cardiomyopathy.
A variety of other blood tests may be done, including those to check your kidney function and look for anemia and thyroid problems. Your iron level may be measured. Having too much may indicate an iron overload disorder called hemochromatosis. Accumulating too much iron in your heart muscle can weaken it and cause cardiomyopathy.
Treatments of Cardiomyopathy
The patient may need to stay in the hospital until acute symptoms subside.
Because the heart dysfunction is usually reversible, and the women are usually young, everything possible will be done to ensure survival.
This may include taking extreme measures such as:
- Use of a balloon heart pump (aortic counter pulsation balloon)
- Immunosuppressive therapy (such as medicines used to treat cancer or prevent rejection of a transplanted organ)
- Heart transplant
For most patients, however, treatment focuses simply on relieving the symptoms. Some symptoms resolve on their own without treatment.
Septal myectomy : Septal myectomy (also called septal myomectomy) is open-heart surgery for people with hypertrophic obstructive cardiomyopathy and severe symptoms. It is generally used in younger patients and when medicines aren't working well.
In septal myectomy, a surgeon removes part of the thickened septum that is bulging into the left ventricle. This widens the pathway in the ventricle that leads to the aortic valve and improves blood flow through the heart and out to the body. The tissue that is removed does not grow back. If necessary, the mitral valve can be repaired or replaced at the same time. This surgery is often successful, and the person can return to a normal life with no symptoms.
Surgically implanted devices : Surgeons can place several different types of devices in the heart to help it beat more effectively. One device is a pacemaker, which electronically helps maintain normal heart rhythm. Sometimes, doctors choose to use a biventricular pacemaker, which coordinates contractions between the heart's left and right ventricles
A left ventricular assist device (LVAD) helps the heart pump blood to the body. LVAD can be used as a long-term therapy or as a short-term treatment for people who are waiting for a heart transplant.
An implantable cardioverter defibrillator (ICD) is used in people who are at risk of life-threatening arrhythmia or sudden cardiac death. This small device is implanted in the chest and connected to the heart with wires. If the ICD senses a dangerous change in heart rhythm, it will send an electric shock to the heart to restore a normal heartbeat.
Heart transplant : In this surgery, a doctor replaces a person's diseased heart with a healthy heart from a person who has recently died. It is a last resort for people with heart failure when all other treatments have failed.
Alcohol septal ablation: In this procedure, a doctor injects ethanol (a type of alcohol) through a catheter into the small artery that supplies blood to the thickened area of heart muscle. The alcohol kills the cells and the thickened tissue shrinks to a more normal size. Blood can flow freely through the pathway in the ventricle that leads to the aortic valve, and symptoms improve.
- Digitalis to strengthen the heart's pumping ability
- Diuretics (water pills) to remove excess fluid
- Low-dose beta-blockers
A low-salt diet may be recommended. Fluid may be restricted in some cases.
Daily weighing may be recommended. A weight gain of 3 or 4 pounds or more over 1 or 2 days may be a sign of fluid buildup.
Patients who smoke and drink alcohol will be advised to stop, since these habits may make the symptoms worse.
Prevention of Cardiomyopathy
Eat a well-balanced, nutritious diet, exercise to increase cardiovascular fitness, and avoid cigarettes and alcohol. Your doctor may advise you to avoid getting pregnant again if you have had heart failure during a previous pregnancy. Examples of lifestyle choices include:
- Quitting smoking
- Eating a healthy diet and maintaining a healthy weight
- Getting regular physical exercise
- Avoiding the use of alcohol and illegal drugs
People also can control high blood pressure, high blood cholesterol, and diabetes by:
- Getting regular checkups with their doctors
- Following their doctors' advice about lifestyle changes
- Taking medicines as directed
Some types of cardiomyopathy, such as inherited forms, can't be prevented. Restrictive cardiomyopathy can't always be prevented because it occurs as the result of another disease. Sometimes, underlying diseases can be prevented or treated early enough to stop restrictive cardiomyopathy from developing.
It may be possible to prevent sudden cardiac death if doctors can identify a person at high risk of this event and treat him or her with an implantable cardioverter defibrillator.