Functional singular ventricle

Introduction

The heart is made up of four chambers, two on the top and two on the bottom.

• atria – the two top chambers that receive the blood that flows into the heart
• ventricles – the two bottom chambers that pump the blood back out of the heart.

Children with a functional singular ventricle only have one ventricle that is large or strong enough to pump blood back out of the heart. 

Having a functional singular ventricle is a congenital heart defect. A congenital heart defect is a difference in how your child’s heart has grown during pregnancy.

Signs and symptoms of a functional singular ventricle can range from mild to severe, depending on whether the ventricle:

• is too small or weak
• is missing a valve
• has not grown at all.

Signs and symptoms can look different depending on how severe the condition is. Some common symptoms include:

• cyanosis – when there is a blue or purple tint to lips, skin, and nails
• difficulty breathing
• difficulty feeding
• being very sleepy or not responding to others
• weak pulse in the arms and legs  
• a lower number of wet nappies than expected.

A functional singular ventricle usually develops during the first 8 weeks of pregnancy. This means the condition is usually picked up early on regular ultrasound scans.

If this happens, you will have another scan called a fetal echocardiogram.

The fetal echocardiogram is like the regular ultrasound scans that are done during pregnancy. The scan uses sound waves to show a detailed picture of your baby’s heart, its structure, and how well it is pumping blood. 

A fetal echocardiogram is usually done between weeks 18-24 of pregnancy. If your baby is diagnosed with a heart defect, you will need to have regular scans and checks until your baby is born to make sure there are no other issues. 

Some babies will not have their singular functional ventricle picked up until birth.

Babies who are diagnosed at birth might:

• look a bit blue
• have trouble breathing
• have an abnormal whooshing sound in their heart, known as a murmur.

The paediatrician who checks your baby after they are born will order an echocardiogram to check their heart to diagnose any issues.

Generally, it is not possible to replace or rebuild a ventricle that is missing or not working properly. 

Treatment will focus on supporting the heart to pump blood as well as it can without becoming overworked. 

This will look different for every child, but usually involves a series of surgical procedures done in a specific order.

These procedures aim to: 

• get the level of oxygen in your child’s blood as close to normal as possible
• improve their general well-being
• lower the risk of conditions like stroke, where the brain does not get enough blood.

Staged reconstruction procedures are done using open heart surgery. Open heart surgery is when your child’s doctor opens the chest wall to get access to the heart.

Treatment for your child will depend on their individual needs and may look different depending on the type of heart defect they have.