(Echocardiography, Echo, Cardiac Ultrasound, Cardiac Ultrasonography, Cardiac Doppler, Transthoracic Echocardiogram, TTE)

Procedure Overview

What is an echocardiogram?

An echocardiogram is a noninvasive (the skin is not pierced) procedure used to assess the heart's function and structures. During the procedure, a transducer (like a microphone) sends out ultrasonic sound waves at a frequency too high to be heard. When the transducer is placed on the chest at certain locations and angles, the ultrasonic sound waves move through the skin and other body tissues to the heart tissues, where the waves echo off of the heart structures. The transducer picks up the reflected waves and sends them to a computer. The computer interprets the echoes into an image of the heart walls and valves.

An echocardiogram may utilize one or more of four special types of echocardiography, as listed below:

  • M-mode echocardiography
    This, the simplest type of echocardiography, produces an image that is similar to a tracing rather than an actual picture of heart structures. M-mode echo is useful for measuring heart structures, such as the heart's pumping chambers, the size of the heart itself, and the thickness of the heart walls.

  • Doppler echocardiography
    This Doppler technique is used to measure and assess the flow of blood through the heart's chambers and valves. The amount of blood pumped out with each beat is an indication of the heart's functioning. Also, Doppler can detect abnormal blood flow within the heart, which can indicate a problem with one or more of the heart's four valves, or with the heart's walls.

  • color Doppler
    Color Doppler is an enhanced form of Doppler echocardiography. With color Doppler, different colors are used to designate the direction of blood flow. This simplifies the interpretation of the Doppler technique.

  • 2-D (2-dimensional) echocardiography
    This technique is used to visualize the actual structures and motion of the heart structures. A 2-D echo view appears cone-shaped on the monitor, and the real-time motion of the heart's structures can be observed. This enables the physician to see the various heart structures at work and evaluate them.

Other related procedures that may be used to assess the heart include resting or exercise electrocardiogram (ECG or EKG), Holter monitor, signal-averaged ECG, cardiac catheterization, chest x-ray, computed tomography (CT scan) of the chest, electrophysiological studies, magnetic resonance imaging (MRI) of the heart, myocardial perfusion scans, radionuclide angiography, and ultrafast CT scan. Please see these procedures for additional information.

Reasons for the Procedure

An echocardiogram may be performed for further evaluation of signs or symptoms that may suggest:

  • atherosclerosis - a gradual clogging of the arteries over many years by fatty materials and other substances in the blood stream

  • cardiomyopathy - an enlargement of the heart due to thickening or weakening of the heart muscle

  • congenital heart disease - defects in one or more heart structures that occur during formation of the fetus, such as a ventricular septal defect (hole in the wall between the two lower chambers of the heart)

  • congestive heart failure - a condition in which the heart muscle has become weakened to an extent that blood cannot be pumped efficiently, causing buildup (congestion) in the blood vessels and lungs, and edema (swelling) in the feet, ankles, and other parts of the body

  • aneurysm - a dilation of a part of the heart muscle or the aorta (the large artery that carries oxygenated blood out of the heart to the rest of the body), which may cause weakness of the tissue at the site of the aneurysm

  • valvular heart disease - malfunction of one or more of the heart valves that may cause an obstruction of the blood flow within the heart

  • cardiac tumor - a tumor of the heart that may occur on the outside surface of the heart, within one or more chambers of the heart (intracavitary), or within the muscle tissue of the heart

  • pericarditis - an inflammation or infection of the sac that surrounds the heart