What is Eisenmenger Syndrome?

The heart has two sides, each responsible for different functions. The right side pumps blood to the lungs, where it receives oxygen. After being oxygenated, the blood travels to the left side of the heart, from which the organ pumps it into the aorta, a large vessel that circulates blood to the rest of the body. Valves open to allow blood to flow into the heart's chambers and arteries, and close to prevent blood from flowing backward through the heart.

The cause of the condition is a shunt or hole between the main blood vessels or chambers of the heart, with which an individual is born. Several heart defects can lead to Eisenmenger syndrome. In each case, the pressure of blood traveling through the shunt results in increased pressure in the pulmonary artery. With time, this damages the blood vessels in the lungs. Eisenmenger syndrome happens when blood begins to flow backward through the shunt, which causes oxygen-rich blood to mix with oxygen-poor blood, lowering the amount of oxygen being pumped to the rest of the body.

Several congenital heart defects can lead to the development of Eisenmenger syndrome:

• Ventricular Septal Defect: a hole between the left and right ventricles. This defect is the most common cause of Eisenmenger syndrome.
• Patent Ductus Arteriosus: a hole between the pulmonary artery that carries oxygen-poor blood to the lungs and the aorta, which carries oxygen-rich blood to the rest of the body.
• Atrial Septal Defect: a hole between the wall that separates the left and right atria.
• Atrioventricular Canal Defect: a hole in the middle of the heart, in the wall that separates the atria (upper chambers) from the ventricles (lower chambers). Additionally, some of the heart's valves may malfunction.

Many symptoms of Eisenmenger syndrome develop due to a lack of oxygenated blood in the tissues and organs. Symptoms include abdominal swelling, tingling and numbness in the fingers and toes, coughing up blood, racing or skipped heartbeats (palpitations), large, rounded fingernails or toenails, quick-onset fatigue, cyanosis (bluish or gray skin, fingers, toes, and lips), chest tightness or pain, dizziness, fainting, and headaches. Someone with Eisenmenger syndrome may also experience shortness of breath during physical activities and at rest.

Possible complications of Eisenmenger syndrome include:

• Arrhythmias: An irregular heartbeat may occur as a result of the thickening and enlarged walls of the heart and low oxygen levels. Also, some arrhythmias lead to blood pooling in the heart's chambers, which can create a blood clot. If the blood clot travels outside the heart, it can block an artery, leading to a heart attack, pulmonary embolism, or stroke.
• Sudden Cardiac Arrest: An arrhythmia can lead to sudden cardiac arrest -- the sudden loss of heartbeat, consciousness, and breathing.
• Heart Failure: Increased pressure in the heart can lead to the muscle becoming weaker and less effective in its pumping ability. This may eventually lead to heart failure.
• Erythrocytosis: The kidneys release a hormone that increases the production of red blood cells, which raises the risk of developing blood clots.

If a physician suspects Eisenmenger syndrome, he may order one or more tests:

• An Electrocardiogram (ECG) measures the heart's electrical activity.
• An Echocardiogram allows a doctor to see how blood flows through the heart; this can show if the heart has a defect.
• Chest X-rays can show enlargement of the heart or pulmonary artery.
• Cardiac Catheterization can measure the blood pressure in the heart's chambers and blood vessels, the amount of blood in the heart and lungs, and the size of a septal defect.
• A Walking Test measures someone's tolerance to mild physical activity.

There is no cure for Eisenmenger syndrome, and medication is the primary treatment. Medications that control heart rhythm, iron supplements, blood-thinning medications, and vasodilators can help improve symptoms and prevent serious complications. People with Eisenmenger syndrome may need to take antibiotics before dental or medical procedures, as well.

Doctors may recommend phlebotomy to a patient whose high red blood cell count is causing symptoms such as visual disturbances, headaches, and difficulty concentrating. In this procedure, a machine drains some blood from the body to decrease the red blood cell count. The patient typically receives intravenous (IV) fluids to help replace those lost during the procedure.

Those who do not respond to other treatment methods may eventually need a heart and lung transplant or a lung transplant and surgical repairing of the hole in the heart. Physicians do not generally recommend surgery to repair the congenital heart defect the individual has developed Eisenmenger syndrome, as the procedure is life-threatening.

People with Eisenmenger syndrome require careful monitoring by a cardiologist specializing in congenital conditions throughout their lifetime. How well the patient fairs depends on whether he has any other medical conditions and the age at which high blood pressure in the lungs first occurs. Symptoms typically get worse with time.