Heart failure due to cardiopmyopathy means the heart muscle has lost its power to do the work it needs to do; it still functions, but not as effectively as it should. In this episode of Second Opinion, you'll learn about the causes and treatment of heart failure and how today's technology, including artificial hearts and heart transplants, is saving lives.

The heart is essentially a muscle, about the size of a fist, whose main job is to pump blood to all parts of the body, bringing needed nutrients and oxygen and delivering waste products for removal by other organs.  The heart has four chambers. The upper two are the atria (the right and the left atrium) and the lower two are the right and left ventricles. These chambers contract in a regular sequence, or rhythm (the heartbeat); the contractions enable the heart to pump blood to all parts of the body.  The rhythm of the contractions is controlled by the heart's "pacemaker," a group of cells in the right atrium (called the sinoatrial node,  SA node, or sinus node) that generate electrical impulses.  This is the "normal" rhythm, usually at a rate of 60 to 100 beats a minute.  These impulses travel across the heart's chambers, making them contract.

There are several kinds of cardiomyopathy - and at least two ways to classify them.   Sometimes doctors are unable to discover a specific cause for an individual's cardiomyopathy. In this case, the condition is known as primary cardiomyopathy.  Secondary cardiomyopathy does have specific causes.  Ischemic cardiomyopathy is caused by a chronic lack of oxygen to the heart muscle because of coronary artery disease.  Non-ischemic cardiomyopathy is not caused by coronary artery disease, but by some other cause, and is often connected to diseases of other organs.  Both kinds of cardiomyopathy can be chronic (long-standing) or acute (sudden and unexpected).  For more information about the causes of cardiomyopathy, see Heart Failure Key Point #1.

Another classification system involves describing the condition of the heart itself. 

• Dilated (or congestive) cardiomyopathy is the most common type.  The heart muscle stretches (dilates), becomes thinner and weaker, and doesn't pump normally.  This often leads to congestive heart failure.  
• Congestive heart failure means the weakened heart action is causing excess body fluids to back up into the lungs and elsewhere because the heart cannot effectively move blood forward.
• Dilated cardiomyopathy can also lead to abnormal heart rhythms called arrhythmias or dysrhythmias.  For more information about arrhythmias, watch the "Heart Rhythm Disorder" episode of Second Opinion.
• Hypertrophic cardiomyopathy means the heart muscle (especially, the left ventricle) thickens (or "hypertrophies").  In one form of this disease, the thickening obstructs the flow of blood into and out of the heart, referred to as hypertrophic obstructive cardiomyopathy; more than half the time, this condition is hereditary.
• Restrictive cardiomyopathy is another type.  The heart muscle becomes hard, stiff, or rigid, which makes it more difficult for the ventricles to be filled with blood between heartbeats.

The symptoms of cardiomyopathy can vary, depending on the type, but in general they include:

• Swollen feet, ankles and/or hands; distended veins
• Shortness of breath, especially with and following physical exertion or when lying down
• Fatigue
• Dizziness 
• Chest pain (technical name: angina pectoris) caused by an inadequate blood supply to the heart muscle
• Irregular heartbeat (technical name: arrhythmia)