Cardiac ultrasonography (echocardiography) uses ultrasound waves to produce an image of the heart’s structure and function, to measure the direction and speed of blood flow that allows computing the blood pressure inside the heart. Standard echocardiography produces a two-dimensional image of a cross section, or slice, of the heart, its chambers and valves, and the large blood vessels of the heart. Doppler echocardiography bounces sound waves off the blood cells within the heart or blood vessels, and measures the speed and direction of flow. By using blood flow velocity data, it is possible to calculate pressure gradients between the corresponding cardiac chambers. Contemporary cardiac ultrasound technique allows high accuracy diagnosis of most abnormalities, precise evaluation of lesion severity and appropriate scheduling of coronary interventions or surgery. The test is painless and does not use radiation.