The inside of a normal heart.

Double inlet left ventricle is a congenital defect (the baby is born with it) in which the left and right atria (plural for atrium) of the heart are connected to the same ventricle. In some cases, one of the ventricles of the heart may be extremely small.

The human heart has four chambers: the left atrium and right atrium (plural: atria) at the top, and the left and right ventricles on the bottom. Blood circulates through the atria and the ventricles to and from the rest of the body via arteries (which carry blood away from the heart) and veins (which carry blood to the heart).

In a normal heart, blood that needs oxygen enters the right atrium and right ventricle of the heart through the vena cavas. From there, it travels to the lungs via the pulmonary artery to pick up oxygen. Blood that has picked up oxygen from the lungs comes into the left atrium. From there, it goes into the left ventricle. The left ventricle pumps this oxygenated blood through the aorta to the rest of the body.

Babies with double inlet left ventricle have an intact left ventricle (the pumping chamber of the heart that pumps blood to the body) and a small right ventricle (the pumping chamber that pumps blood to the lungs). Both atria supply blood to the left ventricle. As a result, oxygen-rich blood and oxygen-poor blood are combined. This mixture of blood flows to the baby’s lungs and body. Double inlet left ventricle is also called common ventricle or single ventricle.

What causes double inlet left ventricle?

The cause of double inlet left ventricle is unknown, but the defect is likely to occur early in a pregnancy while the baby’s heart is developing.

What are the symptoms of double inlet left ventricle?

Symptoms of double inlet left ventricle usually appear in the early weeks of a baby’s life and include:

  • Blue skin (cyanosis)
  • Failure to gain weight normally
  • Trouble breathing
  • Swollen legs or abdomen
  • Pale skin
  • Poor feeding
  • Sweating
  • Fast heartbeat
  • Heart murmur (an unusual heart sound)
  • Fluid buildup around the lungs
  • Heart failure

Many babies with double inlet left ventricle have other abnormalities in the heart or the main arteries. These abnormalities can block the flow of blood to the lungs.

How is double inlet left ventricle diagnosed?

The doctor will perform a physical examination and listen to the baby’s heartbeat with a stethoscope in order to hear if there is a heart murmur. The doctor may also order various tests, including:

An electrocardiogram to measure the heart’s electrical activity Cardiac catheterization (a thin tube is inserted into a vein and advanced to the heart to observe how the heart is functioning) -- Echocardiogram, or ultrasound imaging of the heart --Magnetic resonance imaging, a test that produces very clear pictures, or images, of the human body with a large magnet, radio waves, and a computer

How is double inlet left ventricle treated?

Double inlet left ventricle is treated with surgery to repair the defect. Several surgeries may be needed in order to make the heart work effectively. In most cases, the heart can be repaired to the point where the child can lead a relatively normal life.

With surgery, blood circulation through the body and into the lungs can be improved. Surgeries most commonly performed to treat double inlet left ventricle lead up to a surgery called the Fontan procedure.

If blood flow to the pulmonary artery is restricted, a small tube called a shunt can be surgically placed from an artery attached to the aorta to the pulmonary artery. If there is too much blood flow to the lungs, the surgeon may perform a pulmonary artery banding, which protects the pulmonary arteries from high blood pressure.

The first surgery may have to be performed within the first few days of the baby’s life. The baby usually goes home after the first surgery. A pediatric cardiologist will decide when the baby should undergo the second surgery. The follow-up surgery (or initial surgery if the baby was not operated on in the first few days of life) is called the Hemi-Fontan or Glenn shunt procedure. This operation usually is performed when the baby is 4-6 months old.

The baby’s skin still may appear blue after the first operation(s). The Fontan procedure usually is done when a child is 3 to 6 years old. After the final stage of surgery, the child no longer will have blue skin. Although the Fontan procedure does not result in normal blood circulation in the body, it does improve the circulation and allows the child to grow.

A child may need additional types of surgeries for related defects or to extend survival while waiting for the Fontan procedure. The Fontan procedure has risks and complications, which your child’s doctor will discuss with you.

Your child’s doctor may prescribe medication before and after surgery. These medications may include:

  • Digoxin to help with heart contractions
  • ACE inhibitors to lower blood pressure
  • Anticoagulants to prevent blood clots
  • Diuretics to remove extra fluid from the body

In addition, children with double inlet left ventricle have to take antibiotics before dental treatment in order to prevent endocarditis (infection of the heart lining).

In the most severe cases of double inlet left ventricle, a surgeon may recommend a heart transplant.

What is the prognosis (outlook) for children who have double inlet left ventricle?

Factors that affect how well a baby with double inlet left ventricle does include:

  • How severe the defect is
  • The overall condition of the baby when the diagnosis is made
  • Whether other heart defects are present
  • Genetic syndromes

Many babies with double inlet left ventricle live to adulthood as a result of advances in surgical procedures. Many people with double inlet left ventricle need regular followups. In addition, they can face various complications and their physical activity can be limited.

When should I call the doctor?

Call your doctor if your child:

  • is having trouble breathing;
  • is not eating well;
  • appears to become easily tired;
  • has skin or lips that are bluish in color;
  • is not growing or gaining weight.


Outcome of patients with double-inlet left ventricle or tricuspid atresia with transposed great arteries.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 6/2/2011…#14786