Stress testing can also be performed in conjunction with echocardiography. Echocardiography uses ultrasound to image different parts of the left ventricle and observes their movement and thickening in real time.
When the heart is relaxed it may get enough blood even in the presence of obstructed coronary arteries. However, during physical activity the heart rate and contractility (or strength of contraction) increases, and the heart muscle or myocardium may thus require more blood and oxygen than these narrowed arteries are able to supply. 
A reduction in blood flow to part of the heart muscle may impair the myocardium’s ability to thicken or contract. However these abnormalities are not often seen on an echocardiogram taken at rest, but can be made to appear during exercise.
Two sets of images are obtained as part of a stress echocardiogram. The first set is taken before exercise while the other set is taken immediately after exercise. Both sets of images are then compared with one another. 
This test is frequently performed to determine whether CAD maybe causing chest pain.
The test is done by a doctor and cardiac sonographer. The scanning itself is painless.
Abraham Salacata, MD, FACC