Echocardiographic features and motion mode patterns of cardiac structures in domestic animals

Echocardiography involves examination of cardiac associated structures utilizing ultrasound. There are two common modes of display that are used for echocardiogaphy. B-mode or two dimensional echocardiography displays the returning echoes as dots whose brightness or gray scale is proportional to the amplitude of the returned echo and whose position obtained consists of a slice of the actual organ. In M-mode echocardiography, a single ultrasound beam is used and returning echoes are displayed as a series of dots along a vertical line. The position of the dot along that line represents the depth of reflecting structure, and the brightness of the dot denotes the strength of the echo. The image that is obtained consists of slice of series of amplitudes displayed along time, which represent contraction of the structures. During echocardiography, the animal is usually examined unsedated, either standing or in a lateral recumbency with the area in contact with the transducer, or the acoustic window, is located either on the left or right side of the thorax, between the 2nd to 5th intercostal spaces, just above the sternum in thorax, between 2nd and 5th intercostal spaces, just above the sternum in domestic animals. In small animals, it is helpful to use a cut-out table to facilitate examination and prevent the occurrence of breathing artifacts. For small animals, a transducer with a 5.0-7.5 MHz transducer can be used, while a large animals, 2.5-3.5 MHz transducer can be used. Through B-mode ultrasonography, several views can be obtained from several images, including right parasternal long axis, right parasternal short axis, left parasternal long axis and left parasternal short axis. Depending on the images and views, different structures of the heart can be viewed, including the left ventricle, right ventricle, left atrium, right atrium, interventicular septum, interatrial septum, mitral valve, tricuspid valve, papillary muscles, chorda tendinae, aorta, aortic valves , pulmonary artery pulmonary valves, left ventricular outflow tract and right ventricular outflow tract. The chambers, aorta and pulmonary artery are usually seen as having hypoechoic walls with anechoic lumen. The valves are usually displayed as hyperechoic lines. In addition the pericardium can be seen as hypoechoic lines on the far side of the heart. The different cardiac structures can be viewed easily in horses, water buffalo, cattle sheep, goat and dog. However, it is very difficult to distinguish the different cardiac structures in poultry. In M-mode echocardiography, different motion patterns can be recognized for the various structures of the heart. M-shape pattern is observed in the mitral valve, W-shape pattern for the tricuspid valve eye shape pattern of the apex of the heart, calm sea wave pattern of the left ventricle, chain-link pattern is observed in the aorta, D shape pattern is observed in the pulmonary artery. The above echocardiographic features and M-mode patterns can be used for diagnosis of diseases and disorders in domestic animals.