Cardiac Diseases Cardiomyopathy
What is Cardiomyopathy?
There are two major categories of cardiomyopathy: primary cardiomyopathy, defined as changes in the structure or function of the heart muscle that cannot be attributed to a specific cause, and secondary, which is associated with disorders of the heart or other organs.
Congestive cardiomyopathy is the most common primary form of heart muscle disease.
Other types include hypertrophic and restrictive.
Heart muscle disease related to coronary artery disease is called ischemic cardiomyopathy.
The exact frequency of cardiomyopathy is difficult to determine as many cases are not severe, but about 500,000 new cases develop each year in the United States.
Instead of afflicting the elderly like most other heart diseases, heart muscle disease more commonly strikes younger people.
This group of disorders directly damages the muscle, impairing its ability to pump blood to other parts of the body.
What Causes Cardiomyopathy?
The causes of primary cardiomyopathy are frequently unknown.
Some possible causes in congestive cases are infectious or noninfectious heart muscle inflammation, excessive alcohol consumption, nutritional deficiencies, complications of childbirth, and genetic disorders.
Hypertrophic cardiomyopathy appears to be an inherited disease.
Restrictive cardiomyopathy is usually caused by a disease called amyloidosis, which is associated with cancers of the blood.
Men seem to be affected by congestive cardiomyopathy more often than women.
Most cases of cardiomyopathy cannot be prevented.
Avoiding smoking and excessive alcohol intake, ensuring proper nutrition, and regular exercise are the only known preventive measures.
How is Cardiomyopathy Diagnosed?
In congestive cardiomyopathy, the heart becomes enlarged and weakened and is unable to pump effectively. Symptoms of heart failure develop.
Hypertrophic cardiomyopathy, in contrast to the congestive type, involves an enlargement or overgrowth of the heart muscle, usually that of the left ventricle, but sometimes the right chamber is also involved.
In one form of hypertrophic disease, the septumthe wall between the two ventriclesbecomes enlarged and obstructs the flow of blood from the left ventricle into the aorta.
The mitral valve also may be distorted by the thickened septum, leading to mitral insufficiency.
The major symptoms are shortness of breath, dizziness or fainting, chest pain, and cardiac arrhythmias.
The condition usually can be diagnosed by characteristic physical findings, electrocardiogram, echocardiogram, and, if doubt still exists, cardiac catheterization and radionuclide angiography.
A biopsy of the heart wall tissue may help distinguish between the different types of cardiomyopathy.
How is Cardiomyopathy Treated?
- Lifestyle Changes
Patients with cardiomyopathy should avoid cigarette smoking, excessive alcohol intake, excessive salt consumption, and drugs that may have a toxic effect on the heart.
Maintaining normal weight and blood pressure are important because this reduces the heart's workload.
In some cases of hypertrophic cardiomyopathy, stressful physical activity should be limited.
- Drugs for Cardiomyopathy
In cases of congestive, restrictive, and ischemic cardiomyopathy, treatment focuses on relieving symptoms and improving function.
Drugs include digitalis (digoxin), diuretics, steroids (to relieve inflammation), and ACE inhibitors.
For hypertrophic cardiomyopathy, drugs include beta-blockers and calcium-channel blockers.
- Surgery for Cardiomyopathy
Ventricular assist devices may be employed for some patients as either a bridge-to-transplantation or as a destination therapy.
When used as a bridge-to-transplantation, the assist device helps to keep a critically ill patient alive until a suitable donor heart organ can be identified.
For patients who are too sick or otherwise ineligbile for a transplant, certain assist devices can be used as a destination, or final, therapy.