A detailed ultrasound examination used when a specific question cannot be answered fully by a standard echocardiogram.
Transoesophageal echo, usually shortened to TOE, uses a flexible ultrasound probe passed through the mouth into the oesophagus. Because the oesophagus lies immediately behind the heart, the probe can obtain detailed images without the lungs, ribs or chest wall getting in the way.
TOE is selected for particular questions. It is not simply a better version of a standard echocardiogram. It may be considered for detailed valve assessment, suspected endocarditis, assessment for a blood clot, artificial valves, previous valve repair or planning selected cardiac procedures.
Dr Mark Cassar personally performs and interprets TOE, with the findings considered alongside the reason for the test and the wider clinical picture.
Many patients will first have a transthoracic echocardiogram. A dobutamine stress echocardiogram answers a different question about the heart under controlled stress.
TOE can provide detailed moving images of the heart chambers, valves and nearby blood vessels. It may clarify the mechanism and severity of valve narrowing or leakage, identify changes that raise concern for endocarditis, assess the left atrium and left atrial appendage for thrombus, and define structural abnormalities before surgery or catheter-based treatment.
No scan can exclude every diagnosis by itself. Findings must be considered with symptoms, examination, blood tests, the standard echocardiogram and other imaging.
TOE provides close views of valve anatomy, artificial valves and previous repairs when standard imaging leaves uncertainty.
It can assess for intracardiac thrombus and changes associated with endocarditis, but results are interpreted with the complete clinical picture.
The treating team reviews your medical history, medicines, allergies, swallowing difficulties, dental problems and previous reactions to sedation. You will usually need to fast, but exact instructions about food, drink, diabetes treatment and anticoagulation come from the treating team.
Local anaesthetic throat spray is commonly used and sedation may be offered. You usually lie on your side while the probe is guided into the oesophagus. Monitoring continues throughout. Temporary sore throat, discomfort and drowsiness can occur. Less common complications include reactions to sedation, breathing or rhythm problems, dental injury, bleeding and injury to the throat or oesophagus.
The examination time varies with the clinical question. Results are interpreted alongside the standard echocardiogram, history, examination and other investigations.
The usual first ultrasound test and sufficient for many cardiac questions.
Provides detailed tissue characterisation and assessment of heart muscle.
Useful for selected structural questions, the aorta and coronary anatomy.
Some findings require valve, endocarditis or structural-heart multidisciplinary review.
Not in every situation. TOE gives clearer views of selected structures but is invasive. Standard echocardiography remains the appropriate first test for many questions.
Many examinations use throat spray with sedation. Sedation usually makes you relaxed and drowsy but does not necessarily make you fully unconscious.
The test can be uncomfortable, particularly as the probe passes through the throat. Local anaesthetic and, where appropriate, sedation reduce discomfort.
Do not stop anticoagulants or antiplatelet medicines unless the treating team specifically instructs you to do so.
You will usually need to fast. Follow the exact written guidance from the treating team about water, medicines and diabetes treatment.
If you receive sedation, you should not drive yourself home and will usually need a responsible adult to accompany you. Follow the restrictions provided.
Dr Mark Cassar can review the clinical question, explain whether TOE is likely to help and discuss the appropriate next step.
