Assessing the left-sided pulmonary veins with the help of TEE

In this video from our Transesophageal Echocardiography Essentials course, Andrew Houghton, MD, will teach you how to find the left-sided pulmonary veins using TEE, how to assess flow using colour and PW Doppler, and when to use each method.

Targeted towards cardiologists in training, internists, anesthesiologists, emergency physicians, cardiac physiologists, and cardiac sonographers, this course teaches you everything you need to know about performing a standard TEE exam. You’ll learn when a TEE should be ordered and what needs to be done to ensure the safety of your patient during the process. You’ll also learn how to obtain the standard views and how the standard views can be modified to obtain some of the more atypical views.

Locating the left upper pulmonary vein on transesophageal echocardiography (TEE)

[00:03]

In this lesson, we’re going to learn how to locate and assess the left-sided pulmonary veins. Let’s begin with the left upper pulmonary vein. And to find this vessel, let’s begin with the four-chamber view. This view is found with the TEE probe in the mid-esophageal position. I’d suggest starting with a transducer imaging plane angle of 0 degrees, though this may require some optimization to avoid any foreshortening, but the optimal four-chamber view is normally found somewhere between 0 and 20 degrees.

Using the mid-esophageal four-chamber view

[00:40]

So here we have the mid-esophageal four-chamber view, we have both atria and both ventricles clearly in the image. Now, the left upper pulmonary vein that we are looking for is located just off the edge of the sector just here, adjacent to the left atrium. So in order to bring the left upper pulmonary vein into view, we are going to have to make one or two further manipulations. 

Adjusting the TEE probe to visualize the left upper pulmonary vein

[00:17]

The manipulations that we're going to make are to turn the TEE probe towards the patient’s left and also to withdraw the probe very slightly, and this should start to bring the left upper pulmonary vein into view. And so here we’ve made those probe manipulations, and you’ll notice that we’ve also increased the transducer imaging plane angle to around 30 degrees. And making all those changes has now brought the left upper pulmonary vein into view. And you’ll notice that the left upper pulmonary vein inserts into the left atrium in a relatively vertical orientation. This is in contrast to the left lower pulmonary vein, which we’ll see shortly, inserts in a more horizontal orientation. 

Adjusting the imaging plane angle for the left upper pulmonary vein

[01:49]

Here we have a different patient and this serves to illustrate that sometimes we need very different imaging plane angles, here 75 degrees, to obtain views of the left upper pulmonary vein. The vein is located here, and just adjacent to it, is the left atrial appendage. And in between the two is the posterolateral ridge, also known as the ligament, or fold, of Marshall.

Using color Doppler to locate the pulmonary veins

[02:16]

The pulmonary veins are often easier to see when we switch on color Doppler. We can see then the flow in the pulmonary vein which is entering the left atrium. In fact, I’d suggest that you switch on color Doppler from the outset when you’re hunting for each of the four pulmonary veins, as it does make it somewhat easier to locate them.

Pulsed-wave Doppler for pulmonary vein flow assessment

[02:37]

As well as color Doppler, we should also perform pulsed-wave Doppler. And we do this by placing the sample volume approximately one centimeter into the mouth of the pulmonary vein. Current guidelines recommend that we should do this in any two of the four pulmonary veins in order to thoroughly assess flow patterns. And here’s the characteristic appearance of pulsed-wave Doppler in the left upper pulmonary vein.

Interpreting pulsed-wave Doppler waveforms in the pulmonary veins

[03:04]

And the flow pattern has three distinct components. First of all, we have what’s called the S wave, which corresponds to antegrade flow in the pulmonary vein entering the left atrium during ventricular systole. Immediately following the S wave, we have the D wave, and that also corresponds to a further phase of antegrade flow in the pulmonary vein entering the left atrium during ventricular diastole. And then after the D wave, we have what is often called the A wave, or the AR wave, and this corresponds to retrograde flow back up the pulmonary vein during atrial contraction.

Timing pulmonary vein waveforms using the ECG tracing

[03:49]

And we can time each of these waves using the ECG trace on the screen. So the ventricular systole, or S wave, occurs just after the QRS complex. The ventricular diastole, or D wave, occurs during diastole, and the A wave, which corresponds to atrial contraction, occurs as you would expect just after a P wave. If a patient is in atrial fibrillation, then they will not have an A wave.

Pulmonary vein flow patterns in diastolic dysfunction

[04:20]

Flow patterns in the pulmonary veins can of course tell us a great deal about cardiovascular hemodynamics. This patient has left ventricular diastolic dysfunction, and we’re seeing a pseudonormal restrictive filling pattern in their left upper pulmonary vein flow. In other words, we have equalization in the size of the S and D waves. Normally, the S wave is taller than the D wave.

Pulmonary vein Doppler findings in mitral regurgitation

[04:47]

Assessment of pulmonary vein flow patterns can be particularly valuable in mitral regurgitation. A specific indicator of severe mitral regurgitation is systolic flow reversal, in other words, an inverted S wave. Although, this only applies if the regurgitant jet doesn’t impinge directly upon the pulmonary vein being assessed.

Locating the left lower pulmonary vein on TEE

[05:11]

Let’s now move on to the left lower pulmonary vein, and to find this we advance the probe a little further down the esophagus and turn it a little further toward the patient’s left. And here we can appreciate how the left lower pulmonary vein inserts into the left atrium in a more horizontal orientation than the left upper pulmonary vein. As with the left upper pulmonary vein, we assess the anatomy using 2D imaging and better assess flow patterns using color and pulsed-wave Doppler.