Transplant Center

The heart is a muscular pump about the size of a fist located under the breastbone (sternum) between the lungs. There are four hollow chambers in the heart: the right and left upper chambers (atrium) and right and left lower chambers (ventricles). The heart muscle expands and contracts ("beats") and four valves open and close between the chambers and major blood vessels in an organized manner moving the blood continuously through the chambers and into the main circulatory system. Blood brings oxygen and nutrients to all the organs and removes waste products via the lungs, kidneys and liver. (www.itns.org/education)

We measure a heart's function by the amount of blood it pumps. Normally the heart pumps 60 to 70 percent of the blood in it. This is called the ejection fraction (EF). When the muscle is weak or damaged the heart can't pump blood as well and the EF falls. In order to pump more blood the heart may increase in size and beat faster (increase pulse). We consider the heart function to be severely reduced when the EF falls to 35 percent or below.

The diagnosis of cardiomyopathy indicates that there is a disease that has caused the heart muscle to enlarge. As a result, the heart cannot pump blood effectively to all of the organs and tissues in the body and fails (heart failure). Fluid backs up in the blood vessels, the lungs, liver, abdomen and legs. Because of the lack of oxygen and nutrients to the rest of the body, other organ systems can begin to fail also. (www.itns.org/education)

The major reasons for heart failure include the following:

1. You have a type of heart failure that causes the heart to get bigger and pump poorly. Some of these types of heart failure that may cause you to have what your doctor describes as a dilated heart of heart failure are:

• Viral (infection)
• Post-partum (period of time after pregnancy)
• Alcohol (occurs in some chronic alcoholics)
• Drug Abuse
• Idiopathic (cause unknown)

2. If your heart has been damaged by a myocardial infraction, or heart attack, this may cause your heart to pump poorly or may cause you to have severe or frequent chest pain (angina). This type of heart failure may be described as or can be a result of:

• Ischemic (coronary artery disease, temporary loss of blood supply to the heart)
• High blood pressure

3. If you were born with a heart that does not work well:

• Congenital

4. If your heart has become unable to pump correctly because it has become still or the ventricles are thick and unable to pump blood effectively to the rest of the body this type of congestive heart failure may be described as:

• Hypertrophic (enlarged heart)
• Restrictive

When your heart can no longer be helped with medications or by other surgery your doctor may refer you to be evaluated for a heart transplant.

- Content adapted from http://www.itns.org/ITNS_education.php