Case Studies In Small Animal
Two-dimensional echocardiogram/Color flow Doppler
This is a longitudinal view of the left ventricle (LV), left atrium (LA), and aorta (AO) taken from the right side in systole. A portion of the anterior mitral valve leaflet and its chordal structures (arrows) are partially obstructing the left ventricular outflow tract.
When the color flow Doppler is used to look at blood flow in the same orientation as the view above, two high velocity jets can be identified originating from the same site in the left ventricle (LV) during systole. One jet projects into the aorta (AO) and the other projects into (and curls around within) the left atrium (LA). Both originate from the site of obstruction seen in the echocardiogram above.
Video clip of an echocardiogram of the mitral valve from another cat with the same disease
Within this continuous loop of one cardiac cycle you can see the septal (anterior) mitral valve leaflet and chordal structures appear in the left ventricular outflow tract during systole. Look again at the top picture on this page to identify the region where these structures appear in systole. Time systole and diastole by watching the heart as it contracts and relaxes. Then watch the structures impinge upon and then occlude the outflow tract in systole. If the motion is too fast for you to follow, click the "Pause" or "Stop" buttons on Windows Media Player and then use your mouse cursor to move the horizontal slider slowly back and forth to see the motion at a slower speed. A portion of the cranial papillary muscle can be seen in the left ventricular chamber on the left side of the video at about the arrowhead. Note that it can be seen pulling chordae tendineae into the outflow tract.
Video clip of color flow Doppler echocardiogram from the same cat
Two turbulent jets can be seen - one projecting back into the left atrium and the other going out into the aorta. Note that both jets originate from the region in the outflow tract where the chordal structures and anterior mitral valve leaflet impinge on the outflow tract, as seen above.
©Mark D. Kittleson, D.V.M., Ph.D. All rights reserved.