What is Transesophageal Echocardiography?

Transesophageal echocardiography (TEE) is basically an echo study performed from behind the heart with a probe placed in the esophagus (food pipe). Since the esophagus lies just behind the heart, TEE produces clearer pictures of the heart’s movement than a standard echocardiography taken from outside the chest. This test is ideal for looking at the heart’s valves, communications within the heart, and for discerning blood clots in the heart.

In such cases, Dobutamine stress echocardiography, which is a type of stress echocardiography, is performed. Dobutamine is a medicine that increases the heart rate, heart contractility and the blood pressure, thereby mimicking the effects of exercise. It consists administering gradually increasing doses of an intravenous infusion of Dobutamine to mimic the effects of exercise. Simultaneous monitoring of the patient’s ECG, blood pressure and viewing the heart wall motion on 2D Echocardiogram and Colour Doppler is performed.

Indications for this test include establishing a diagnosis of coronary artery disease, determining myocardial viability before angioplasty or coronary artery bypass surgery, assessing prognosis after myocardial infarction or in chronic angina, and evaluating risk of surgery in patients with heart problems who are undergoing non cardiac operations. Also patients with an abnormal baseline ECG (eg: left bundle branch block (LBBB) are advised Dobutamine stress test as a routine treadmill stress test is often fallacious in this setting

What are the indications?

• To evaluate the cardiac chambers, especially the atria and their appendages, for the presence of a blood clot i.e. thrombus to rule out cardiac source of embolus in cases of strokes and in cases of severe mitral valve disease (mitral stenosis) before valvuloplasty and electric cardioversion for atrial fibrillation.
• To look for patent foramen ovale (small defect in the interatrial septum) in cases of unexplained stroke. The colour flow Doppler helps in detection of left to right shunt, whereas a contrast venous injection of agitated normal saline is useful in detection of a right to left shunt across the patent foramen ovale.
• To look for presence of vegetations on the cardiac valves or paravalvular or valvular abscess, to assess evidence of subacute bacterial endocarditis, in known valvular heart disease cases presenting with fever and a fresh murmur (abnormal heart sound).
• To assess the extent and nature of atrial septal defects and decide about the suitability of device closure, when regular transthoracic echo does not give a satisfactory picture.
• To assess the mechanics of prosthetic cardiac valves, when transthoracic echo is unable to provide sufficient information.
• To diagnose the aortic conditions like acute dissection, aortic trauma, etc.

What are pre-test instructions?

• Eight hours complete fasting prior to the test is essential. (even water is not allowed).
• To bring along all the prior investigations.
• A relative or a friend has to accompany the patient for this test.

What are post-test instructions?

• After the test, patient should avoid any kind of hot and spicy food or drink for at least four hours. Thereafter, patient can resume with the regular diet.

The report would be given to patient along with the CD in about 30 minutes after the test is over.

What are the risks or complications?

• Sore throat and mild difficulty in swallowing is common after the procedure and rarely is prolonged for more than 24 hours.
• Minor complications such as transient hypoxia (reduced oxygenation), hypotension (fall in blood pressure), hypertension (rise in blood pressure), bronchospasm, heart block, arrhythmias occur in less than 3% of cases.



Major complications such as death, esophageal perforation, serious arrhythmia (abnormal heart rhythm, congestive heart failure and laryngospasm are uncommon and occur in less than 0.3% of patients