echocardiography
Meaning of echocardiography: The number most often quoted from the study is ejection fraction, the share of blood the left ventricle pushes out with each beat.
Definition of echocardiography
Echocardiography is an ultrasound examination of the heart. A handheld transducer sends high-frequency sound into the chest and detects the echoes returning from tissue boundaries, and a computer converts their timing into a moving picture. It shows the chambers, valves and walls of the heart as they work, in real time, using no ionizing radiation at all.
What can it measure?
Several techniques run within one study, each answering a different question.
| Technique | What it shows |
|---|---|
| Two-dimensional imaging | Chamber size, wall thickness, valve appearance, movement of each wall segment |
| M-mode | A single line traced over time, for precise measurement of thickness and motion |
| Doppler | Speed and direction of blood flow, which converts into pressure across a valve |
| Color Doppler | Flow overlaid on the image, making leaking and narrowed valves visible at a glance |
From these come the routine answers: how strongly the heart squeezes, whether a valve is leaking or narrowed, whether a wall moves poorly because its blood supply is impaired, whether fluid has collected around the heart, and whether pressure in the lung arteries is raised.
How do the approaches differ?
The standard transthoracic study places the transducer on the chest wall and images between the ribs. It is quick, painless and repeatable, but bone and air scatter sound, so the picture suffers in people with lung disease or a large body habitus. A transesophageal study passes a small probe down the esophagus, which lies directly behind the heart, giving a far clearer view of the valves, the left atrial appendage and prosthetic hardware; it requires sedation. A stress study images the heart before and immediately after exercise or a drug that speeds it up, exposing wall segments that move normally at rest but fail under demand.
When is it used?
Echocardiography is the first-line imaging test for breathlessness of uncertain cause, for a newly heard murmur, after a heart attack, and for suspected congestive heart failure. It is repeated to track a leaking valve over years, and to monitor heart function during cancer treatments that can weaken the muscle. Because it carries no radiation and no injection in its basic form, it is also the standard heart study in pregnancy and in children.
Also known as
Used in a sentence
Echocardiography was performed to evaluate the heart's valve function and overall pumping ability.
Good to know
Echocardiography performed through the chest wall is distinguished from the transesophageal approach, performed through the esophagus, since the latter can provide a closer view of certain structures, such as the heart valves, that may be less clearly seen from outside the chest.
Word origin
Where “echocardiography” comes from
Formed from echo-, from Greek echo, meaning sound, combined with cardio-, from Greek kardia, meaning heart, and -graphy, from Greek graphein, meaning to write or record.