A method of obtaining an image of the structure and movement of the heart with ultrasound. Echocardiography is a major diagnostic technique used to detect structural, and some functional, abnormalities of the heart wall, heart chambers, heart valves, and large coronary arteries. It is also used to diagnose congenital heart disease (see heart disease, congenital), cardiomyopathy, aneurysms, pericarditis, and blood clots in the heart.
A transducer (an instrument that sends out and receives sound signals) is placed on the chest, or an ultrasound probe is passed into the oesophagus using a flexible endoscope. Ultrasound waves are reflected differently by each part of the heart, resulting in a complex series of echoes, which are viewed on a screen and can be recorded or the results printed out. Developments such as multiple moving transducers and computer analysis give clear anatomical pictures of the heart.
Doppler echocardiography measures the velocity of blood flow through the heart, allowing assessment of structural abnormalities, such as septal defects.
The use of ultrasonics (see ULTRASOUND) for the purpose of examining the HEART. By thus recording the echo (hence the name) from the heart of ultrasound waves, it is possible to study, for example, the movements of the heart valves as well as the state of the interior of the heart. Safe, reliable and painless, the procedure cuts the need for the physically interventionist procedure of CARDIAC CATHETERISATION.
n. the use of *ultrasound waves to investigate and display the action of the heart as it beats. Used in the diagnosis and assessment of congenital and acquired heart diseases, it is safe, painless, and reliable and reduces the need for cardiac *catheterization. M-mode echocardiography uses a single beam of ultrasound. The image produced is not anatomical but permits precise measurement of cardiac dimensions and the diagnosis of valvular, myocardial, and pericardial disease. 2-D echocardiography uses a pulsed array of ultrasound beams to build up a moving image on a TV monitor of the chambers and valves of the heart. In Doppler echocardiography ultrasound reflected from moving red blood cells is subject to the Doppler effect (change of frequency with velocity relative to the observer), which can be used to calculate blood flow and pressure within the heart and great vessels. It is useful in the diagnosis and assessment of valve disease and intracardiac shunts. In transoesophageal echocardiography (TOE) the ultrasound probe is mounted on an oesophageal endoscope. The examination from within the oesophagus allows the probe to be placed directly against the back of the heart, which enables improved visualization of the posterior structures.
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