In this video by Andrew Houghton, MD, you will learn how to use TEE to obtain the mid-esophageal four-chamber view to assess regional and global right ventricular function, measure RV size and tricuspid annulus diameter, and assess the tricuspid valve leaflets.
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[00:00:00] In this lesson, we're going to learn how to obtain the mid-esophageal four-chamber view of the right heart, which shows us the right atrium, the tricuspid valve, and the right ventricle. This view is obtained with the transesophageal echo probe in the mid-esophageal position, pointing anteriorly, so we obtain the cut through the right heart. I'd suggest starting with a transducer imaging plane angle of 0
[00:00:30] degrees, however, a little bit of optimization may be necessary to avoid any foreshortening of the chambers. Normally, an optimal view will be obtained somewhere between 0 and 20 degrees. To begin with, the mid-esophageal four-chamber view will look something like this. We have an imaging plane angle of 0 degrees and we are seeing the left atrium, mitral valve, and left ventricle. And then we have the right atrium, tricuspid valve, and right ventricle.
[00:01:00] And ideally, we would like to center the right heart a little more towards the middle of the image sector. So, what we do is we turn the TEE probe towards the patient's right and this sweeps across the heart and helps to center the right heart in the middle of the sector. And so, this is the view that we end up with. We can see now that the right heart is a little more centered in the middle of the sector.
[00:01:30] And in this view, we can look at the size and anatomy of the right atrium. We can look for any right atrial masses. We can also look at the size of the right ventricle. We can look at this visually in comparison to the left ventricle, and normally, the right ventricle is no more than two-thirds of the size of the left ventricle. We can also quantify the right ventricular dimensions and we'll show you where to take these linear measurements, in just a moment.
[00:02:00] In addition, we can look at the tricuspid valve. And then before chamber view, we can see two of the three tricuspid leaflets. This is the septal leaflet, here and then over here, we have either the anterior or posterior tricuspid valve leaflets, depending upon how deeply down the esophagus we have advanced the probe. In order to quantify the size of the right ventricle, we should measure its internal diameter
[00:02:30] at the base point of the right ventricle and also at its midpoint and we should make this measurement in end-diastole. So, this is where the measurements are made, at the base of the right ventricle and also at the midpoint of the right ventricle and we should time these measurements in the cardiac cycle, using the ECG trace so that they are made at the end of diastole. If the diastolic diameter at the base is greater than 42 mm or
[00:03:00] a mid-level is greater than 35 mm, then this indicates right ventricular dilatation. We should also measure the tricuspid annulus, between the hinge points of its leaflets, at both end-systole and end-diastole. This is a useful measurement for cardiothoracic surgeons, in planning tricuspid valve repair. And this is where we make that measurement, this is the tricuspid annulus diameter,
[00:03:30] measured between the hinge points, of the leaflets at end-diastole. Again, we use the ECG trace to time that. And here's the same measurement, between the hinge points, made at end-systole. Finally, we should undertake a Doppler assessment flow, through the tricuspid valve, in the mid-esophageal four-chamber view. We should begin by applying color Doppler to have a look at flow patterns
[00:04:00] and here we can see this yellowy red jet of tricuspid regurgitation through the valve. This is a relatively small and mild jet of regurgitation. And if the alignment is appropriate, we can perform continuous wave Doppler of flow, through the tricuspid valve, to obtain a spectral Doppler trace, like this. And we can measure the peak velocity of a tricuspid regurgitant jet,
[00:04:30] to assist in the estimation of pulmonary artery systolic pressure.