Cardiomyopathy

Definition

Definition of Cardiomyopathy
Cardiomyopathy (literally "heart muscle disease") is the measurable deterioration of the function of the myocardium (the heart muscle) for any reason, usually leading to heart failure; common symptoms are dyspnea (breathlessness) and peripheral edema (swelling of the legs). People with cardiomyopathy are often at risk of dangerous forms of irregular heart beat and sudden cardiac death. The most common form of cardiomyopathy is dilated cardiomyopathy.

Symptoms

Symptoms of Cardiomyopathy
Symptoms and signs may mimic those of almost any form of heart disease. Chest pain is common. Mild myocarditis or cardiomyopathy is frequently asymptomatic; severe cases are associated with heart failure, arrhythmias, and systemic embolization. Manifestations of the underlying disease (e.g., Chagas' disease) may be prominent. Most patients with biopsy-proven myocarditis report a recent viral prodrome preceding cardiovascular symptoms.

EKG abnormalities are often present, although the changes are frequently nonspecific. A pattern characteristic of left ventricular hypertrophy may be present. Flat or inverted T waves are most common, often with low-voltage QRS complexes. Intraventricular conduction defects and bundle branch block, especially left bundle branch block, are also common. An echocardiogram is useful to detect wall motion abnormalities or a pericardial effusion. Chest radiographs can be normal or can show evidence of congestive heart failure with pulmonary edema or cardiomegaly.

Causes

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:

1. Long-term high blood pressure
2. Heart valve problems
3. Heart tissue damage from a previous heart attack
4. Chronic rapid heart rate
5. Metabolic disorders, such as thyroid disease or diabetes
6. Nutritional deficiencies of essential vitamins or minerals, such as thiamin (vitamin B-1), selenium, calcium and magnesium
7. Pregnancy
8. Excessive use of alcohol over many years
9. Abuse of cocaine or antidepressant medications, such as tricyclic antidepressants
10. Use of some chemotherapy drugs to treat cancer
11. Certain viral infections, which may injure the heart and trigger cardiomyopathy
12. Iron buildup in your heart muscle (hemochromatosis)
13. Genetic conditions

Diagnosis

Diagnosis of Cardiomyopathy

1. Chest X-ray: An image of your heart will show whether it's enlarged.
2. Echocardiogram: An echocardiogram uses sound waves to produce images of the heart. Your doctor can use these images to examine the size and function of your heart and its motions as it beats. This test checks your heart valves and helps your doctor determine the cause of your symptoms.
3. 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.
4. 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.
5. 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.
6. 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.

Treatment

Treatment of Cardiomyopathy
Treatment depends on the type of cardiomyopathy, but may include medication (conservative treatment) or iatrogenic/implanted pacemakers for slow heart rates, defibrillators for those prone to fatal heart rhythms, ventricular assist devices (LVADs) for severe heart failure, or ablation for recurring dysrhythmias that cannot be eliminated by medication or cardioversion. The goal of treatment is often symptom relief, and some patients may eventually require a heart transplant. Treatment of cardiomyopathy (and other heart diseases) using alternative methods such as stem cell therapy is commercially available but is not supported by convincing evidence. Due to the severity of the disease, treatment requires the use of numerous chemicals and drugs, which have to be taken for the rest of the patient's life.

Prognosis

Prognosis of Cardiomyopathy
Consult with your doctor.

Prevention

Prevention of Cardiomyopathy
In many cases, you can't prevent cardiomyopathy. Let your doctor know if you have a family history of the condition. If cardiomyopathy is diagnosed early, treatments may prevent the disease from worsening.

You can help reduce your chance of heart failure by avoiding some of the conditions that can contribute to a weak heart, including the abuse of alcohol or cocaine or not getting enough vitamins and minerals. Controlling high blood pressure with diet and exercise also prevents many people from developing heart failure later in life.