Heart Failure Heart failure occurs when the heart becomes too weak to effectively pump blood through the body. Blood flow out of the heart slows, causing blood to back up in the blood vessels around the lungs. Fluid then builds in the lungs and tissues of the body. Patients may experience shortness of breath and swelling in the legs and feet. Other symptoms can include fatigue, inability to exercise, dizziness, chest pain (angina) and loss of appetite.

According to the National Heart, Lung and Blood Institute, about five million people in the U.S. have heart failure; 550,000 new cases are diagnosed each year. Common causes of the condition include coronary artery disease, prior heart attack and high blood pressure. Heart failure may also be caused by cardiomyopathy (disease of the heart muscle), heart valve disease, abnormal heart rhythms, congenital heart disease, alcohol or drug abuse, thyroid disease, chemotherapy or radiation therapy (for cancer).

Treating Heart Failure There are many treatments for heart failure. Initially, doctors may try to treat the symptoms with diet, lifestyle changes and medication. Patients with heart failure may need to limit intake of salt, fluid and cholesterol. Doctors also recommend prescribed exercise, weight loss, stopping smoking and limiting alcohol intake. Medications can help reduce build up of fluid, lower blood pressure, slow heart rate or strengthen the heart. For patients with blockages from coronary artery disease, doctors may also recommend angioplasty or bypass surgery. When treatments are no longer effective, patients may require a heart transplant.

Heart Pumps for Heart Failure Researchers have been developing heart pumps for patients who are in danger of dying, but don't have a donor heart available. For suitable candidates, the heart pump takes over the work of the heart, rhythmically forcing blood through the body. In some cases, a heart pump can take the burden off a weak heart, giving the organ time to recover and foregoing the need for a transplant.

One type of heart pump is the Jarvik 2000. The device operates differently from other heart pumps. Instead of taking over the heart beat, the Jarvik 2000 boosts the flow of blood through the heart. The heart continues to beat normally while the pump adds, or forces out, extra blood flow.

The small pump is about the size of a "C" battery. It is surgically placed within the left ventricle and powered through a cable attached to a connector behind the ear.

Once in place, the pump provides extra blood flow for the patient and can be adjusted to accommodate different activities. An exterior cable connects a flow control dial to the pump's battery. When patients require more blood flow (like during exercise), the dial is turned up increasing the flow of blood from the pump and saving the heart from extra exertion. At bedtime or rest, the dial can be turned down to slow the speed of blood flow and allow the patient to sleep.

Currently, the Jarvik 2000 is being used as a bridge-to-transplant buying time for patients until a donor heart becomes available for transplant. Doctors hope to also be able to use the Jarvik 2000 as a permanent device, providing enough assistance to delay or prevent the need for transplant.

Jarvik 2000 for Children Children can develop heart failure from congenital heart defects or illnesses. Unfortunately, current heart pumps are much too large to implant in a child's tiny heart. However, researchers are trying to develop designs useful in children. Investigators are looking for ways to miniaturize the Jarvik 2000 to make a device that would be appropriate for children.

There are some stumbling blocks to overcome when developing a heart pump for a child. Researchers can't simply make the parts smaller because children have different flow and pressure requirements from adults. Dial controls for flow rates are important for children, but must have some type of access protection to prevent a child from inappropriately changing the flow rate of the device.

Another obstacle is the growth of the child. As the child grows, a small pump may not be adequate for his/her needs. However, researchers are hopeful, that as medical advances are made, doctors will eventually have other options for these children. The National Institutes of Health have provided a grant to support the development of the heart pump for children. Doctors hope to have a child-sized Jarvik 2000 pump ready for use within two years.

For information on the Jarvik 2000: University of Maryland Medical Center, http://www.umm.edu/heart/jarvikQA.html

For general information on heart failure: American Heart Association, http://www.americanheart.org, or contact your local chapterbr/> Heart Failure Online, http://www.heartfailure.org
Heart Failure Society of America, http://www.hfsa.org
National Heart, Lung, and Blood Institute, http://www.nhlbi.nih.gov