ULTRASONIC examination of the heart represents one of the new, developing examination modalities that has attracted considerable attention and offers promise as an important diagnostic tool in cardiac disease. Its popularity stems directly from its noninvasive, nonionizing nature, which permits easy examination, even at the bedside if necessary. The unique ability of ultrasound to differentiate solid structures of the heart from the blood without the use of contrast agents can be used to obtain information about cardiac structure. Records of the movement of cardiac elements also offer important information about heart function. I shall describe this examination technique and indicate conditions in which ultrasonic examination is valuable clinically.
The development of naval sonar devices in the years after World War I represents the beginning of the technology on which echocardiography is based. High-speed oscilloscopes, developed for the nondestructive testing of metals, provided the link between the long-range sonar devices