The inside of a normal heart.

What is double inlet left ventricle?

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.

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.