Learn to find your way around the mitral valve with the help of TEE imaging in this informative video. Get a career boost by learning TEE and standing out amongst the rest of the pack.
Your teacher, Andrew Houghton, MD, is head of cardiac imaging at Grantham & District Hospital.
This video was taken from our Transesophageal Echocardiography Essentials course, which comes with 10 CME credits. Register for a free trial and check it out!
[00:00:00] The mitral valve seen here, from a surgical perspective, is a complicated structure and comprises not just the mitral valve leaflets but also the annulus, the chordae tendineae, and the papillary muscles. Transesophageal echo is an excellent imaging modality for assessing the structure and function of the mitral valve because in most TEE views, the mitral valve is relatively close
[00:00:30] to the transducer. The main body of a mitral valve consists of two leaflets. An anterior leaflet and the posterior leaflet but lie within a mitral valve annulus. Transesophageal echo allows very accurate measurement of both the minor access and also the major access of the mitral valve annulus, which is very useful for surgeons who are planning mitral valve repair.
[00:01:00] The anterior leaflet occupies approximately one-third of the circumference of the annulus. The posterior leaflet occupies about two-thirds, and both leaflets are divided into three segments or scallops. For the anterior leaflet, these are labeled A1, A2, and A3 and for posterior leaflet, they are labeled P1, P2, and P3. The leaflet segments are numbered,
[00:01:30] starting from the anterolateral commissure, which lies nearest to the left atrial appendage and this is where the A1 and P1 segments are. Across to the posteromedial commissure, where the A3 and P3 segments are. The posterior leaflet segments are relatively well-defined because of these indents that lie between the P1 and P2, and the P2 and P3 segments. However, the anterior segments are generally less well-defined
[00:02:00] because the anterior leaflet is a more continuous structure. Transesophageal echo provides us with multiple different views of the mitral valve and each view shows us different permutations of segments. And it's important to know which segments are seen in each view, so that we can interpret any abnormalities appropriately. During each of the mitral valve lessons in this course, we'll be focusing very closely on which segments are seen within each view.
[00:02:30] But we have an example here, two views of the heart. On the left-hand side of the screen, we have a mid-esophageal four-chamber view, which is equivalent to what we're seeing in the diagram just alongside it. The four-chamber view is obtained with an imaging plane angle of 0 degrees and this cuts through the mitral valve leaflets at the level of the A2 and the P2 segments. So, here, we have the
[00:03:00] A2 segment and here, we have the P2 segment. On the right-hand side of the screen, we have a different view of the mitral valve. This is the long-axis view of the heart. This is obtained at an imaging plane angle of 135 degrees. As you can see from the diagram, this also cuts through the A2 and P2 mitral valve segments. So, here, we have the A2 segment. Here, we have the P2 segment.
[00:03:30] Assessment of the mitral valve is not just about the valve leaflets and annulus but it's also about the subvalvular apparatus, the chordae tendineae, and the papillary muscles. And we get to see the subvalvular apparatus particularly well on transgastric views. This is a two-chamber transgastric view, which shows the left ventricle here, the papillary muscles, the chordae tendineae, and their insertions into the
[00:04:00] mitral valve leaflets.