Transesophageal echocardiogram

Echocardiogram is an image of the heart using ultrasound. An ultrasound beam is transmitted into the body using a device known as transducer. The echo received from the body is processed by the computer in the machine to give an image of the heart.
Transesophageal echocardiogram or TEE test, is obtained by introducing a special type of transducer, also called a TEE probe, through the throat into the food pipe (esophagus) and stomach. Usual echocardiogram is obtained by placing the transducer or probe on the chest.
Lungs may overlap the heart intermittently while imaging the heart from the chest wall. This is because the lungs cover part of the heart when you breath in. This will interfere with the image quality.
In TEE as the echo probe is in the food pipe, there is no interference by the overlapping of lungs. Esophagus or food pipe is just behind the heart so that the distance which the ultrasound beam has to travel to reach the heart is also small. For both these reasons, the images obtained by TEE has much superior quality compared to external imaging.
TEE is very useful in picking up small clots and infective material on heart valves. This helps in treatment of potentially life threatening diseases like infection of the heart valves. It can detect defects in the wall between the upper chambers of the heart known as ASD very well.
TEE is widely used by heart surgeons to get real-time assessment of the heart after repair of birth defects and abnormalities of heart valves. As it can be done from the operation theatre itself, surgeon can immediately correct any residual defects before coming out of anaesthesia.
Usual echocardiography with probe kept on the chest is difficult during open heart surgery as the chest wall is open. Using a device over the open chest is likely to affect the sterility of the procedure and lead to contamination and infections. But there is no such problem with TEE as it does not interfere with the operating field – the imaging is from the food pipe behind the heart.
Now is there any disadvantage for transesophageal echocardiogram? The most important disadvantage is the semi invasive nature. Some feel it uncomfortable to have the long probe introduced through the throat. This can be reduced by giving sprays and application of local anaesthetic gel.
Those with obstructions or diseases of the food pipe can have complications when the device is introduced. So, the operator should be well trained in the procedure and in interpretation of the images. Supporting personnel to monitor the patient during procedure is also necessary.