Cardiomyopathy is a condition in which the heart muscle becomes inflamed and can't work as well as it should. In dilated cardiomyopathy, the ventricles, or chambers of the heart, become enlarged and stretched. The walls of the ventricles become thinner and the heart muscle weakens. The weakened heart is unable to efficiently pump blood to meet the body's need for oxygen, leading to heart failure. Some patients develop abnormal heart rhythms (arrhythmias). The stretched walls of the ventricles may interfere with the ability of the heart valves to close completely, increasing the risk of development of blood clots in one of the chambers. In some cases, a blood clot can break free, travel through the circulatory system and become lodged in a narrow artery elsewhere in the body. In the brain, a trapped clot can cause a stroke.

Dilated cardiomyopathy is most commonly seen in adults. However, the condition can occur in children. One study found dilated cardiomyopathy to affect about 1.13 of every 100,000 infants. The most common causes in children are a viral infection that affects the heart muscle (myocarditis) and neuromuscular disease (most commonly muscular dystrophy).

Waiting for a Heart Transplant

Children who develop serious heart failure (like from dilated cardiomyopathy) may require a heart transplant to stay alive. Last year, 162 heart transplants were performed in children five and under. But the number of pediatric patients who need a heart exceeds the quantity of donor hearts. As of November 16th, there were 101 children (5 and under) who were waiting for new hearts.

With a serious shortage of pediatric donor hearts, a child on the waiting list can die before a new heart becomes available. One option that may be available is extracorporeal membrane oxygenation (ECMO). ECMO is a child-sized heart-lung bypass machine that temporarily takes over the work of the heart and lungs. In some cases, it can provide support until the child's body recovers from an illness and the natural heart is strong enough to work on its own. But if recovery isn't possible, ECMO can temporarily keep a child alive until a donor heart becomes available.

Research suggests, when used as a temporary bridge to transplantation, up to 57 percent of patients on ECMO survive to transplantation. However, the treatment has some serious risks. Children need to be heavily sedated. Heparin, an anti-clotting agent, must be added to the blood to keep it from clotting in the tubing. That can increase the risk of bleeding. ECMO patients also require blood products. Although donor blood is thoroughly screened, there is still a slight risk of acquiring a transfusion-related infectious disease. Air bubbles can form in the tubes that carry blood and oxygen. These tiny bubbles can become lodged in the body. Infants on ECMO are also at risk for developing an infection.

The Berlin Heart®

Some infants and children who are waiting for a heart transplant may be offered the Berlin Heart®. It is a type of ventricular assist device, or mechanical heart pump. The Berlin Heart can be used to support the left side of the heart, right side or both sides. The model for children is called the EXCOR® Pediatric.

Most ventricular assist devices are implanted into the chest. The pump for the Berlin Heart, on the other hand, stays outside the chest. It's connected to the heart by tubes that extend through the skin. For patients with left-sided heart failure, oxygenated blood on the left side of the heart flows from the lower chamber into the Berlin Heart. The device then pumps the blood into the aorta, where it travels on to the rest of the body. In right-sided heart failure, deoxygenated blood from the right side of the heart flows into the Berlin Heart, then is pumped into the pulmonary artery where it travels on to the lungs.

The Berlin Heart is not yet approved for use in the U.S. However, doctors can petition the FDA on a case-by-case basis for permission to implant the device in children who have no other options. It comes in four pump sizes, so it can be used in infants, toddlers and children. It is not a permanent solution for heart failure. However, it may be another option for children who are awaiting heart transplantation. Ron Gajarski, M.D., a Pediatric Cardiologist at the University of Michigan Medical Center, says in some cases, children may be able to go home while they wait for a donor heart.

For information on the Berlin Heart®, http://www.berlinheart.com.

For information about heart transplantation:

United Network for Organ Sharing (UNOS)

For general information on cardiomyopathy:

American Heart Association

The Cardiomyopathy Association

National Heart, Lung and Blood Institute