Double inlet left ventricle

Causes

DILV is one of several heart defects known as single (or common) ventricle defects. People with this condition generally have a large left ventricle (the pumping chamber of the heart that supplies the body with blood), and a small right ventricle (the pumping chamber that supplies the lungs with blood).

In the normal heart, the right and left lower chambers (ventricles) receive blood from the right and left upper chambers (atria). Oxygen-poor blood returning from the body flows to the right atrium and right ventricle. The right ventricle then pumps blood to the pulmonary artery, which carries blood to the lungs to pick up oxygen.

The blood, now oxygen rich, returns to the left atrium and left ventricle. The aorta then carries oxygen-rich blood to the rest of the body from the left ventricle.

However, in those with DILV, only the left lower heart chamber is developed, and both upper chambers carry blood into this ventricle. This means that oxygen-rich blood mixes with oxygen-poor blood. The mixture is then pumped into both the body and the lungs.

DILV can occur with transposition of the great vessels (in which the aorta arises from the small right ventricle and the pulmonary artery arises from the left ventricle), or it can occur with the arteries arising from their "normal" ventricles. Blood flows from the left to right ventricle through a ventricular septal defect (VSD) -- a hole between the chambers.

Double inlet left ventricle occurs in about 5 - 10 of 100,000 live births. The problem most likely occurs early in the pregnancy, when the baby's heart develops. However, the exact cause of DILV is unknown.

Patients with DILV often also have other heart problems, such as:

• Coarctation of the aorta
• Pulmonary atresia
• Pulmonary valve stenosis

Symptoms

Symptoms of DILV may include:

• Becoming tired easily, especially during feeding
• Bluish skin color, called cyanosis (the lips may also be blue), due to low oxygen in the blood flowing to the body
• Failure to gain weight and grow
• Pale skin (pallor)
• Poor feeding
• Sweating
• Swollen legs or abdomen
• Trouble breathing

Exams and Tests

Signs of DILV may include:

• Abnormal heart rhythm, as seen on an electrocardiogram
• Build-up of fluid around the lungs
• Heart failure
• Heart murmur
• Rapid heartbeat

Tests to diagnose DILV may include:

• Chest x-ray
• Measurement of the electrical activity in the heart (electrocardiogram, or ECG)
• Passing a thin, flexible tube into the heart to examine the arteries (cardiac catheterization)
• Ultrasound exam of the heart (echocardiogram)
• Using magnets to create images of the heart (MRI)

Treatment

Surgery is needed to improve blood circulation through the body and into the lungs. The most common surgeries to treat DILV are a series of two to three surgeries. These surgeries are similar to the ones used to treat hypoplastic left heart syndrome and tricuspid atresia.

The first surgery may be needed within the baby's first few days of life. Afterward, the baby will usually go home. The child will usually need to take daily medications and be closely followed by a pediatric cardiologist, who will decide when the second stage of surgery should be done.

The next surgery (or first surgery, if the baby didn't need the procedure mentioned above) is called the bidirectional Glenn shunt or Hemifontan procedure. This surgery is usually done when the child is 4 - 6 months old.

After the child has had the above operations, he or she may still look blue (cyanotic). The final step is called the Fontan procedure. This surgery is usually performed when the child is 18 months - 3 years old. After this final step, the baby is no longer cyanotic.

The Fontan operation does not create normal circulation in the body, but it creates the type of circulation a child can live and grow with.

A child may need more surgeries for related defects or to extend survival while waiting for the Fontan procedure.

The doctor may prescribe your child medication before and after surgery. Medications may include:

• Anticoagulants to prevent blood clotting
• ACE inhibitors to reduce blood pressure
• Digoxin to help the heart contract
• Diuretics

For the most severe cases of DILV, a heart transplant may be recommended.

Outlook (Prognosis)

DILV is usually a very complex, hard-to-treat heart defect. How well the baby does depends on several factors, including:

• Baby's overall condition at the time of diagnosis and treatment
• Presence of other heart abnormalities
• Severity of the defect

Advances in surgical techniques allow many infants with DILV to reach adulthood. However, these children and adults require regular follow-ups, face many complications, and may be limited in the type of physical activities they can pursue.

Possible Complications

Complications of DILV include:

• Clubbing (thickening of the nail beds) on the toes and fingers (late sign)
• Congestive heart failure
• Frequent pneumonia
• Heart rhythm problems

When to Contact a Medical Professional

Prevention

Alternative Names

DILV; Single ventricle; Common ventricle

References

Baldwin HS, Dees E. Embryology and physiology of the cardiovascular system. In: Gleason CA, Devaskar S, eds. Avery's Diseases of the Newborn. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 50.

Update Date: 6/5/2012

Updated by: Kurt R. Schumacher, MD, Pediatric Cardiology, University of Michigan Congenital Heart Center, Ann Arbor, MI. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.