What is a transoesophageal echocardiogram?
A transoesophageal echocardiogram, often shortened to TOE or TEE, is an ultrasound of the heart taken from inside the gullet rather than from the surface of the chest. Because the gullet lies directly behind the heart, with no ribs or lung tissue in the way, the pictures are far more detailed than those of a standard scan. A thin, flexible tube with a small ultrasound probe at its tip is passed through the mouth into the gullet, in much the same way as a gastroscopy.
Why is it done?
It is used when fine detail matters: to look for a blood clot in the upper chamber of the heart before a rhythm procedure, to search for infection on a heart valve, to assess a leaking or narrowed valve and plan its repair or replacement, to examine an artificial valve, to look for a hole between the chambers or the source of a stroke, and to guide procedures such as appendage closure, PFO closure or valve treatment. It is chosen when a standard chest ultrasound cannot answer the question.
How do I prepare?
Do not eat or drink for at least six hours before the test, so that the stomach is empty; you may take essential medication with a small sip of water as instructed. Tell us beforehand about swallowing difficulty, gullet disease, previous gullet surgery, loose teeth or dentures, and about blood thinners, diabetes medication and allergies. Because you will be sedated, you must arrange for someone to drive you home, and you should not drive, operate machinery or sign important documents for the rest of the day.
What happens on the day?
A drip is placed and your heart rhythm, blood pressure and oxygen level are monitored. The back of the throat is sprayed with local anaesthetic, which tastes bitter and makes the throat feel numb and swollen, and sedation is given through the drip so that you become drowsy and remember little of the test. Dentures are removed and a soft mouthguard is placed between the teeth. You lie on your left side and are asked to swallow once as the probe is passed; it does not interfere with your breathing. Pictures are then taken from several positions, and the probe is gently moved and rotated. The recording usually takes ten to twenty minutes.
What to expect afterwards
You rest in the recovery area until the sedation wears off, generally for about an hour. You may not eat or drink until the throat spray has worn off, usually one to two hours, because swallowing is unsafe while the throat is numb; the nurse will tell you when you may start, beginning with sips of water. A mildly sore throat and a hoarse voice for a day are common. Because of the sedation you should be accompanied home, rest for the day and not drive. Your cardiologist can usually discuss the findings with you before you leave, and a full report follows.
Possible complications
This is a safe test in experienced hands, but it is more invasive than a chest ultrasound. Common and minor: a sore throat, hoarseness, mild nausea and a bruise at the drip site. Uncommon: sedation causing low blood pressure or shallow breathing, which is monitored and easily managed; a lip, tooth or dental crown being damaged; and vomiting. Rare but serious: a tear or perforation of the gullet, which occurs in far fewer than one in a thousand cases but may need surgery; significant bleeding; inhaling stomach contents into the lungs; or a disturbance of heart rhythm. Please tell us about any swallowing problems beforehand, as this is the main way of avoiding trouble.
This information does not replace a consultation. Please discuss your own risks and options with your cardiologist.