Echocardiogram Bubble Study

What is an echocardiogram?

An echocardiogram is an ultrasound of the heart. It is also called an "echo." Ultrasound uses sound waves to take pictures of the inside of the body. An echocardiogram is done to get pictures of the heart and the areas around the heart. This information helps doctors understand what your child's heart is doing.

For more information on echocardiograms, including why they are done, how to prepare for the test, and what to expect during an echocardiogram, please read the "Echocardiogram" brochure.

What is a bubble study?

Sometimes we inject a fluid called contrast medium into your child's bloodstream. This helps us get a better picture of your child's heart on the echocardiogram.

One type of contrast medium is saline (sterile salt water) mixed with a gas. Usually, the gas is carbon dioxide, the same gas that makes soda fizzy. When this solution is used it is called a bubble study.

A bubble study lets us follow the path that the bubbles take through the bloodstream. This helps us to find heart or lung problems.

The bubble study is safe. The bubble solution is easily absorbed into your child's bloodstream.

Preparing for a bubble study

To get your child ready for a bubble study, follow the same instructions you follow for a regular echocardiogram.

You should also tell your child that he or she will need an intravenous line (IV) on the day of the test. An IV is a needle in your child's arm, attached to a tube. This lets us put fluids directly into your child's bloodstream.

Eating and drinking before a bubble study

Most children do not need to do anything special to get ready for an echocardiogram. However, if your child is under three years old, he may need a sedative. A sedative is a kind of medicine that will help your child sleep for the test. An echocardiogram works best when the child does not move.

If your child is having a sedative for the test, he must stop eating and drinking several hours before the test. A nurse will call you in the week before the test to make sure you understand what and when your child can eat and drink. The table below also tells you when your child must stop eating and drinking.

What your child can eat and drink before the sleep medicine

Time before test

What you need to know

8 hours

No more solid food, milk, or orange juice. This also means no gum or candy.

Your child can still drink clear liquids. Clear liquids are anything you can see through, such as apple juice, ginger ale, or water.

Your child can also eat Jell-O or popsicles.

6 hours

No more milk or formula.

4 hours

Stop breastfeeding your baby.

2 hours

No more clear liquids. This means no more apple juice, water, or ginger ale. Your child cannot eat any popsicles or Jell-O.

What will happen during the bubble study

Before the test, the nurse will ask your child to change into a hospital gown.

Three people will be in the room to do the test:

  • a doctor
  • a nurse
  • a sonographer, who operates the echocardiogram machine

The doctor will mix the bubble solution in a sterile syringe and inject it into your child's IV. The sonographer will take the pictures with the echocardiogram probe.

Going home after the test

If your child was not given a sedative, he or she can drink as usual. The nurse or doctor will remove the IV and put a bandage on before you and your child go home.

If your child was given a sedative for the test, your child's nurse will tell you what you need to do.

For more information on caring for your child after sedation, please read the Sedation pamphlet.

Getting the results of the test

Your child's doctor will give you the test results and tell you what they mean. It will be 7 to 10 days before the doctor gets the results.

Key points

  • A bubble study is a heart ultrasound that uses a bubbly liquid to help doctors get a better view of the path of blood through the heart.
  • The contrast material is usually sterile salt water and carbon dioxide. It is injected into the body through an IV. It is safe.
  • Your child should prepare for a bubble study in the same way as an echocardiogram. You should also tell your child he or she will need an IV.

Fraser Golding, MD, FRCPC

Jane Best, RN

Jennifer Kilburn, BScN, MN

Carrie Heffernan, RN, MN


At SickKids:

Take your child to register on 4B in the Atrium wing of the hospital, in the Echo Lab.