A T.E.E. is performed by cardiologists to look into the chambers of the heart using ultrasound. This procedure also allows the doctor to check your heart valves to see if they are functioning like they should. A T.E.E can show blood clots in the chambers of the heart that form as a result of an irregular heartbeat. After numbing the throat, an ultrasound probe is inserted into the mouth and down the throat behind the heart where it emits ultrasound to produce images on a screen.