A bubble echocardiogram (echo), also called a bubble saline contrast echo or bubble study, is a non-invasive test that looks at your heart.
Unlike a normal echocardiogram (heart ultrasound), a bubble echo uses an injection of saline (mixed with your blood to form small bubbles) to identify a hole in the heart called a patent foramen ovale (PFO).
What does a Bubble Echocardiogram involve?
A bubble echo is a straightforward test which is performed by a trained physiologist.
To begin the test, you’ll have a cannula (thin plastic tube) inserted into a vein in the back of your hand. A small amount of sterile saline with microscopic bubbles will then be injected. The bubble are best created by mixing the saline with a drop of your own blood. The protein in the blood holds the bubbles in the mixture. You’ll be asked to lie down on your left side with your left arm above your head.
As the bubbles from the injection flows through your bloodstream and into your heart, your physiologist will track them using an echocardiogram. If your heart is normal, the bubbles will only be visible in the right side. If bubbles appear in the left side of your heart, this indicates the valve is still open and you have an ASD or PFO. You will be asked to do certain manoeuvres to see if bubbles cross from right to left- sniffing, and Valsalva, straining down as if pushing hard.
A bubble echo usually takes around 30 to 45 minutes.
Normally, the right and left sides of the heart do not communicate, but in people with an ASD (Atrial Septal Defect) or PFO, blood can flow from left to right, causing strain on the right heart, or right to left, possibly carrying clots with it, that might lead to stroke.
A PFO is a congenital defect where the flap valve that separates the chambers of the heart stays open after birth rather than closing spontaneously. It is present in 25% of the population.
You may need to have a bubble echo if your doctor suspects you have a hole in your heart. Or, the test may also be done if you’ve had an unexpected stroke or heart attack, to identify whether an ASD or PFO could be to blame.
Before having a bubble echo, you’ll have an appointment with your consultant cardiologist who will explain the test to you and answer any questions you may have.
You should continue to take any medications as normal and there is no need to fast before the test.
It’s helpful to drink plenty of fluids and keep yourself warm before your test as this can help will blood flow making it easier to find a vein for cannula insertion.
Recovery & Risks:
Once the test is complete you can continue with your normal activities and you’ll be safe to drive.
Your consultant may share your results with you straight away, or you may be asked to book a follow-up appointment.
If a hole in your heart has been identified, your consultant will talk you through the next steps and most suitable treatment options.
A bubble echo is a very safe test and associated risks are very low when performed by a specialist. The bubbles that are injected are extremely small and will be filtered out by your lungs so will not cause you any harm. Very occasionally, if you have severe migraine, it might cause a headache.