With the ultrasonic examination of the heart via the oesophagus, i.e. transoesophageal echocardiography (TEE), a transducer will be guided through the mouth and down the oesophagus to behind the heart – images will be recorded closer to the heart.
With this method, images of the walls, chambers and valves of the heart are more accurate than with regular echocardiography. The TEE test is often used to check the heart for blood clots before cardioversion. If blood clots are present, cardioversion, i.e. restoring the sinus rhythm with medication or an electric shock, is contraindicated. The procedure usually lasts for up to 60 minutes. A local anaesthetic reducing the gag reflex is firstly applied to the mucous membrane of the mouth for performing the TEE. In addition, an intravenous sedative will also be used, which makes the test significantly more tolerable. Due to the sedative, vehicles cannot be driven for at least 6 hours after the procedure. Patients may not eat or drink for at least 4 hours before the test.