I can arrange for you to have a bubble study at Colchester Hospital or the Essex Cardiothoracic Centre.

A “bubble study” is usually done to see if there are any abnormal communications between the chambers of the heart – ie a “hole in the heart”. This is more common that you might think, with about a quarter of the population having a small flap-like gap between two chambers in their heart – this is almost always of no significance.

What does it involve?

Usually you will already have had a standard echocardiogram first. If not, this will be done just prior to the bubble study. The bubble study involves performing an echo while the patient has an injection of salt water into a vein in their arm.

A small plastic tube, called a cannula, is placed into a vein in your arm or the back of your hand. The cardiac physiologist will then get a good picture of your heart on the echo machine.

The salt water is agitated first to fill it will some tiny harmless bubbles. This is then injected into your arm vein. You will not feel this and it will not affect you. The tiny bubbles will appear on the right side of the heart and be clearly seen on the ultrasound. If any bubbles are seen on the left side, this would indicate a communication between the right and left sides.

Usually this test is done a few times on the one sitting. You may be asked to do some breathing manoeuvres that help force the little flap open – this will be demonstrated to you.

What preparation is needed?

There is no preparation required for this study. It is helpful if you can wear tops that are easy to remove. Please let the receptionist know if you will need help with undressing or if you would like a chaperone.

How long does it take?

If you do not need a standard echo as well, the procedure will take about 20 minutes to do.

What happens after

After the bubble study, you will be given tissue to wipe off the ultrasound jelly, just as for a standard echo. You will also have the cannula removed from your arm and a plaster put over the hole. As for a standard echocardiogram, there are no after effects so you can get on with the rest of your day.

What are the risks?

There are no known risks with cardiac ultrasound. If the probe has to be pressed very hard against your chest, you may get a mild tender area but it would be unusual for you to bruise, unless you are on warfarin. Injecting a small quantity of agitated saline will not cause any harm either.

What are the benefits?

This study helps assess whether you have a hole in your heart or a little flap. Since a quarter of the population have a little flap, very few people actually need anything done about it. It is only in very special circumstances that this hole or flap would need to be closed. Every case is different and the reasons for doing a bubble study and the results will be explained to you in detail.