Patients with cardiomyopathy tend to do much better if they understand their disease, and actively participate in monitoring it and treating it. The purpose of this article is to help patients with cardiomyopathy, and their loved ones, to understand the basics of this disorder, and what they ought to be doing to help themselves.
What is cardiomyopathy? What is heart failure?
Cardiomyopathy is disease of the heart muscle. In most cases, cardiomyopathy causes the heart muscle to become weak. Various medical disorders cause various types of cardiomyopathy, but all types of cardiomyopathy ultimately do the same thing – they reduce the efficient functioning of the heart muscle, and diminish the ability of the heart to meet the needs of the body. When the heart can no longer pump enough blood to meet the needs of the body, heart failure is said to be present.What are the types of cardiomyopathy?
There are three major types of cardiomyopathy – dilated cardiomyopathy, hypertrophic cardiomyopathy, and restrictive cardiomyopathy. The vast majority of patients who develop cardiomyopathy have the dilated form. So, after briefly describing hypertrophic and restrictive cardiomyopathies, we will concentrate on dilated cardiomyopathy for the remainder of this article.Hypertrophic cardiomyopathy is a genetic disorder that causes a chaotic growth of heart muscle cells within the ventricles. The disordered, thickened (or hypertrophic) heart muscle can lead to problems pumping sufficient blood to the body’s organs, and can cause potentially fatal cardiac arrhythmias. Click here for a more detailed discussion of hypertrophic cardiomyopathy.
]i]Restrictive cardiomyopathy is a very rare condition in which the heart muscle is infiltrated, and made stiff, by abnormal cells, protein, or scar tissue. The stiffening of the ventricles restricts the return of blood to the heart, causing the blood to “dam up” into the body’s organs. The most common cause of restrictive cardiomyopathy is amyloidosis, a disease in which protein-like substance is deposited within the body’s tissues. Other causes include sarcoidosis and hemochromatosis.
In dilated cardiomyopathy (often referred to as congestive cardiomyopathy or congestive heart failure), previously normal heart muscle becomes damaged, leading to a generalized weakening of the walls of the cardiac chambers. To compensate for the weakening of their muscular walls, the cardiac chambers dilate. (The dilation of the cardiac chambers, especially of the left ventricle, is often referred to as "remodeling.") The weakening and the dilation of the heart muscle eventually lead to heart failure.
What causes dilated cardiomyopathy?
Because almost anything that damages cardiac muscle can lead to dilated cardiomyopathy, there are many causes.The most common cause of cardiomyopathy in developed nations is coronary artery disease. Heart attacks cause death of heart muscle by obstruction of a coronary artery. While the damage is localized to the region of muscle supplied by that artery, within a few months the entire left ventricle dilates (or remodels) to compensate for the damage. With a small heart attack, the amount of ventricular dilation is minimal. But with a large heart attack or a series of smaller heart attacks, dilated cardiomyopathy becomes extensive, and heart failure ensues.
Another common cause of dilated cardiomyopathy is inflammation of the heart muscle, a condition called myocarditis. Myocarditis is most often caused by viral infections, but can also be caused by bacterial infections and by non-infectious causes such as lupus and other inflammatory diseases.
Alcohol is another cause of cardiomyopathy. In some patients (probably determined by genetic predisposition), alcohol acts as a powerful toxin to heart muscle, directly damaging cardiac cells. Alcoholic cardiomyopathy can be seen after as few of five years of excessive alcohol intake.
