(Amanda Rhee M.D., Farzan Filsoufi M.D.)
Transesophageal echocardiography (TEE) is performed intraoperatively in all patients undergoing valve surgery and is critical to assess and localize valvular dysfunction.
The comprehensive TEE examination of the mitral valve consists of a series of eight cross-sectional views. The mitral valve is studied using four mid esophageal views and four transgastric and deep transgastric views:
Mid esophageal four-chamber view
Mid esophageal mitral commissural view
Mid esophageal two-chamber view
Mid esophageal long axis view
Transgastric basal short axis view
Transgastric two-chamber view
Transgastric long axis view
Deep transgastric long axis view
TEE probe is positioned 30-40 cm from incisors for mid esophageal windows, 40-45 cm for transgastric windows, and 45-50 cm for deep transgastric windows. The mid esophageal views are produced by positioning the transducer posterior to the mid level of the left atrium and directing the imaging plane through the annulus parallel to transmitral flow.
In mid esophageal four-chamber view, the multiplane angle is rotated from 0 to 20 degrees. The P1 segment of the mitral valve is to the right of the image display and the A3 segment to the left. The mid esophageal mitral commissural view is obtained when the multiplane angle is rotated to approximately 60 degrees. In this view, the A2 segment is visualized in the middle of the left ventricular inflow tract, P1 is to the right of the image display, and P3 to the left. The multiplane angle is rotated forward to approximately 90 degrees to develop the mid esophageal two-chamber view. In this view, P3 is to the left of the image display and A1, A2, A3 to the right. Finally, the multiplane angle is rotated 120-160 degrees to visualize the mid esophageal long axis view. Now the P2 segment of the posterior leaflet is to the left of the image display and the A2 segment of the anterior leaflet to the right.
As previously described, Carpentier's functional classification of mitral valve disease is used to describe the mechanism of valvular dysfunction. This classification is based on the opening and closing motions of the mitral leaflets.Valvular dysfunction may present four functional types in the setting of mitral regurgitation. Patients with type I dysfunction have normal leaflet motion with the free edges of the leaflets positioned 5 to 10 mm below the plane of the annulus. Mitral regurgitation in these patients is due to annular dilatation, or leaflet perforation or tear. There is increased leaflet motion in patients with type II dysfunction with the free edge of the leaflet overriding the plane of the annulus during systole (leaflet prolapse). The most common lesions leading to type II dysfunction are chordae elongation or rupture, and papillary muscle(s) elongation or rupture. Patients with type IIIa dysfunction have a restricted leaflet motion during both diastole and systole. The most common lesions are leaflet thickening/ retraction, chordae thickening/shortening/fusion, and commissural fusion encountered in rheumatic valve disease. Mitral regurgitation is usually associated with varying degrees of mitral stenosis. The mechanism of mitral regurgitation in type IIIb dysfunction is restricted leaflet motion during systole. Left ventricular enlargement leading to apico-lateral papillary muscle displacement and chordae tethering causes this type of valve dysfunction.
For each view, we have provided several videos and analyzed valvular dysfunction according to Carpentier's functional classification. The mid esophageal views are completed with color flow Doppler demonstrating the direction and the size of the regurgitant jet.