Double Inlet Left Ventricle (DILV)

What is it?

Double Inlet Left Ventricle is a very rare congenital heart defect where both (right and left) atria of the heart are connected to the left ventricle. In babies with this condition, both the tricuspid valve and the mitral valve let blood flow into the left ventricle. This means that oxygen-rich blood and oxygen-poor blood are mixed. This blood then flows to the baby’s lungs and body. 

Usually, there is a small right ventricle and it is small because it is not used. This type of heart condition is also known as a single-ventricle heart defect because children with DILV only have one ventricle that works.

Sometimes the blood vessels leaving the heart are in the wrong positions. In a normal heart the aorta arises from the left ventricle and the pulmonary arteries arise from the right ventricle.

In DILV, the aorta can arise from the small right ventricle and the pulmonary artery arises from the left ventricle (transposed). Sometimes the arteries are in the correct positions but there is a hole between the two ventricles called a VSD and sometimes both vessels can arise from the same ventricle.

This heart defect is associated with other heart abnormalities such as:

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

1. Double inlet left ventricle  

2. Hypoplastic right ventricle  

3. Transposed aorta 

 4. Functional single ventricle 

 5. Ventricular septal defect

How can it be spotted?

Double Inlet Left Ventricle can be detected at the 20-week anatomy scan or after birth by echocardiogram.

If it is not picked up in the antenatal period, once the baby is born you may see the following signs:

• Bluish colour to the skin and lips due to low oxygen in the blood
• Breathlessness
• Being too tired to feed
• Fast heart rate
• Swollen legs or abdomen
• Failure to gain weight and grow

How can it be treated?

Because this type of heart condition is a single-ventricle heart defect, it cannot be corrected. However, the symptoms can be improved by surgery. Normally several stages of surgery are required to balance and optimise blood flow to the lungs and the body.

These will be open heart surgeries performed under general anaesthetic, the timing of which will depend on the severity of the anomaly, and the general condition of the baby.

Occasionally, there can be too much blood flow to the lungs and in cases like this, surgery (pulmonary banding) will be needed to restrict this excessive flow.

Blalock-Taussig shunt: This is the first surgery that is usually done in the first few weeks after birth and the surgeons will use a small tube to direct blood flow to the lungs. 

Glenn procedure: The second surgery is usually done when the baby is around 6 months of age and the surgeons direct the blood flow from the upper body to the pulmonary artery so that the blood can collect oxygen from the lungs without having to go through the heart

Fontan procedure: This is the third surgery that is usually done when the child is 2 – 3 years old. The surgeons will now be separating the circulation so that no mixing of blood occurs. This also decreases the workload on the single ventricle. This procedure does not create a normal blood circulation in the body but it does improve the circulation.

General information/advice for the future

Babies and children with Double Inlet Left Ventricle will need lifelong followup. This will usually involve repeat tests like echocardiogram, ECG and sometimes cardiac Magnetic Resonance Imaging (MRI) scans. The aim of these check ups is to monitor your child’s heart function so that any future heart problems are diagnosed and treated quickly. 

They may develop other complications such as arrhythmias, blood clots, and pulmonary vascular disease (PVD) and their physical activity can be limited. They may also be on various medications. 

Your cardiologist will advise you about any restrictions on activity that you should be aware of. As your baby will have had open heart surgery, they will have a scar down the middle of the chest, and there will be small scars where drain tubes were used, but these will fade over time.

Ethan’s story

Vicky discovered her son, Ethan, had a range of heart defects during her pregnancy. Despite the huge obstacles they faced, Ethan is now healthy and doing well. This is their story.