Echocardiogram is major mile stone in the history of cardiology,facilitating us to view the internal status of the heart noninvasively.The soundwaves are generated by the piezoelectric crystals in the transducer.These waves reflect at the tissue interface reach the sensor in the transducer which converts the sound waves into electrical impulses to generate an image.This principle is the key in obtaining the images in echocardiography.

Source: Feigenbaum's Echocardiography.
Videos from Wockhardt Heart Center,Kamineni Hospitals,Hyderabad,India.