A Transoesophageal echcocardiogram is the ultrasound imaging of the heart and the blood flow through it.Ultrasound imaging of the heart and the blood flow through it. This is a detailed ultrasound assessment of the heart using a special endoscope (a flexible tube) with an ultrasound transducer which produces ultrasound waves. The probe is passed through your mouth into the oesophagus just behind the heart. The transducer sends ultrasound into the heart and then receives the echo, i.e. the signals that bounce back. The signals are transformed into pictures that show on a screen. Transesophageal echocardiography (TOE) is used if the transthoracic echocardiogram (TTE) doesn’t produce clear results. Compared with transthoracic echo, TOE provides clearer and sharper images because the distance from the probe to the heart is much shorter and the ultrasound waves don’t have to pass through the chest wall and lungs.