Doppler Profiles and Assessment of Diastolic Function

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Doppler Profiles and Assessment of Diastolic Function

Christopher J. Gallagher and John C. Sciarra

Test Note

Anyone who ever took the test will attest to one thing: DIASTOLIC DYSFUNCTION IS A BIG PART OF THE TEST. Repeat, DIASTOLIC DYSFUNCTION IS A BIG PART OF THE TEST.

Tricuspid Valve and Right Ventricular Inflow

The big Mammas of the valve world are the mitral and aortic, with whole lectures dedicated to each one individually. The tricuspid and pulmonic valves usually get lumped together, like third-class steerage passengers on the Titanic. It’s a safe bet that you should put your efforts into the mitral and aortic valves. But, let’s soldier on through the tricuspid valve.

The tricuspid valve has (duh) three cusps. Set in a (normally) low-pressure system, the tricuspid doesn’t “have to” function perfectly. You will normally see some regurg here. Think about it; sometimes the tricuspid valve is removed and not even replaced, and the heart continues to function. Try that with the aortic valve!

You get a dandy view of the tricuspid in the “easiest” view to get, the ME four-chamber. The ME RV inflow–outflow view also gives you a shot at the tricuspid.

Focusing your Doppler on the tricuspid valve will tell you just how severe the tricuspid regurg is. The regurg is severe if:

Also, if the hepatic vein flow profile shows systolic flow reversal, that also indicates severe tricuspid regurgitation. If you think about it, that makes sense. When the heart contracts, if the tricuspid valve doesn’t work, the blood flows back into the right atrium and just keeps on flowing backward, backward, backward, all the way back into the inferior vena cava and back further into the hepatic vein (which feeds into the inferior vena cava).

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Pulmonary Valve and Right Ventricular Outflow

Look at your model of the heart again. The pulmonary valve is the farthest away valve in the heart. No surprise, then, that you sometimes have a hard time getting a good look at it. And getting a good Doppler study through it can be a real pain.

Fortunately, a kind Providence has given us a few good views of the pulmonic valve. The ME RV inflow–outflow view works. If you get that aortic valve in a good en face view (the Mercedes Benz sign), then you will get a 90-degree view of the pulmonic valve.

Another view (not quite as easy to get) is the UE aortic arch SAX view. This view gives you a better chance at getting a Doppler shot down the pipe of the pulmonic valve.

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When you Doppler-ifize the pulmonic valve, you will see some regurg, especially if there is a PA catheter straddling the valve. As with other valves, you can get an impression of the degree of regurg by looking at the size and depth of the regurgitant jet. A big jet means a lot of regurg, a little jet means a little regurg. (Aren’t you glad you went to school for years and years to be able to figure out such complex stuff?)

Since the pulmonic valve lies far afield from the echo probe, getting more quantitative than that just ain’t in the works.

When you see PR, it’s worth thinking about what might be causing it. As with other valves, a poorly functioning valve (endocarditis, carcinoid syndrome, congenital defect) may account for the blood flowing backward. Also, highpressure “downstream” of the valve (pulmonary hypertension, pulmonary embolus) may “overwhelm” a normal valve and cause regurgitation.

Mitral Valve and Left Ventricular Inflow

Test Note

THIS IS THE BIGGIE. THE DOPPLER PATTERNS OF INFLOW FROM THE MITRAL VALVE INTO THE LEFT VENTRICLE ARE EXTREMELY TESTABLE. THESE PATTERNS REVEAL ALL-IMPORTANT DIASTOLIC DYSFUNCTION. ENTIRE LECTURES IN THE REVIEW COURSE ARE DEDICATED TO DIASTOLIC DYSFUNCTION. IF TIME IS SHORT, FOCUS ON THIS MATERIAL AS YOU WILL SEE IT IN SPADES ON THE TEST.

How the blood flows into the ventricle tells a lot about the ventricle’s function during diastole. If the heart is healthy, springy, and not stiff, then the blood will flow in easily. If the heart is sick, stiff, and nonresilient, then the blood will have to “work hard” to fill the ventricle.

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Judging by the puzzled looks in the diastolic dysfunction lectures, it was evident to me that this whole idea is a little hard to absorb. For some reason, the idea of systolic dysfunction is easy to grasp:

The pump doesn’t work, but the concept of diastolic dysfunction is tough.

The loading of the pump doesn’t work.

The world would be a nice place if the mitral inflow patterns were a simple

But noooooooooooooooooooooooooooooooooooooooooooo! Life is not so. Understanding these confusing patterns is the whole crux of understanding diastolic dysfunction.

First, I’ll blast through the patterns, then I’ll go back and try to drag you through the reasoning. PLOW THROUGH THIS STUFF SLOWLY, AND LOOK FOR THE EXPLANATION IN A FEW DIFFERENT BOOKS, FOR DIASTOLIC DYSFUNCTION IS A TOUGHIE.

Now, the reasoning behind the patterns. (The first part is easy—the second is a bit sticky.)

Side note: to acquire the E/A ratio, place the pulse wave circle thing at the tip of the mitral leaflets. For the pulomonary flow go way to the top of the left atrium and put the PW there. You may have to ask a professional for help with this.

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The Heart with Impaired Filling

In your mind’s eye, make the heart a little stiffer, a little less compliant. When the mitral valve opens now, the blood has a harder time rushing into the left ventricle (like trying to blow air into a stiffer balloon; it’s just harder to do, so less goes in). The E wave, then, is blunted. Now the atrium, which didn’t empty too well, is still sort of full, so when the atrium contracts, the A wave will be a little bigger.

The E-to-A ratio has reversed, as seen in the second pattern in the figure at the top of this page.

It would be great if things just stopped right here, because up until now, it’s quite easy to follow.

Alas, from here on out, it gets a little tougher. This is where it pays to look at a bunch of different books (Otto; the TEE review course syllabus) and see how this is explained.

The Yet-More-Noncompliant Heart

Now, let time pass and the heart gets yet more noncompliant and yet stiffer. Now, the atrium really fills up a lot, from a long-standing battle to push blood into the ventricle. When the mitral valve opens, blood now rushes in, not due to a compliant ventricle accepting the blood easily, but from an overfilled atrium ramming the blood down the ventricle’s throat. Then, when the atrium contracts, some more blood is added to the ventricle.

Net result? The third pattern in the figure at the top of page 58, pseudonormalization of the E-to-A ratio.

But wait, that E-to-A ratio looks just like the first pattern, that of the groovy heart with good compliance! It looks normal, but how can that be, because we know it’s abnormal!

Right you are! That pattern is called a “pseudonormalization of the E-to-A ratio.”

Every test-taker in the galaxy just asked himself or herself the same question:

There are a few ways.

The Stiff-as-Hell Heart: No Kidding End-Stage Diastolic Wipeout

Let more time pass and make that heart just as stiff as stiff can be. Now the pattern gets distinct enough to differentiate from the normal pattern, as shown in the fourth pattern in the figure at the top of page 58: restrictive or really bad.

What you are seeing is a thin spike of high pressure as a totally overamped atrium fires into a rock of ventricle. Pressure rises high and fast and falls off fast. Note how thin the E wave is. Then the A wave is just a tiny little thing, because the atrium is so stretched out that it doesn’t have much “oomph” of its own left over.

For completeness’ sake, study the Doppler patterns of the other valves, but FOCUS ON THESE MITRAL PATTERNS. THEY ARE THE KEY TO DIASTOLIC DYSFUNCTION AND WILL APPEAR ON THE TEST.

Now we have spoken of the EA ratio, and the SD (systole, diastole) of the pulmonary vein flow. It is time to put it all together. Here is the diagram you must memorize. And when we say memorize, that means you should be able to draw this in all its detail from memory. If you can, that means you understand the relations of blood flowing into the LV and how it relates to blood flowing into the left atrium. Now don’t rush thru this. Each little detail is important.

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Notice how the IVRT (isovolumic relaxation time) changes. See how the D wave in the pulmonary vein flow dips in diastolic dysfunction, then goes up in pseudo-normalization. Pay attention to the PV-Ar (the atrial reversal part of pulmonary vein flow). Look at how the DT (deceleration time) changes during the E phase of the mitral inflow. Try to imagine these flows happening in the heart and memorize these subtle differences.

This table is graphic and quite precise, but each drawing has a number associated with it. On a test, you may see the image on a screen, or you may just be given the numbers. So here is a table of the numbers. Note, these are not iron clad. Textbooks argue over absolutes, so you may see different numbers in different texts.

Aortic Valve and Left Ventricular Outflow

You don’t really interrogate the LVOT to determine diastolic dysfunction, so this part of the outline is a bit of a “misnomer.” But you do need to look with the Doppler at the aortic valve. The trouble is, to get a good “up the pipe” view of the aortic valve, you need to align the aortic valve in the deep transgastric long-axis view.

AND GETTING THE DEEP TRANSGASTRIC LONG-AXIS VIEW IS HARD AS HELL!

The first (and in my case, nearly every) time you try to get this view, you will advance the probe deep, deep into the stomach, you will anteflex it, pull back and…and…and you get a transgastric mid–short-axis view. The bouncing donut view.

Damn.

You try again, you put that probe in so far you figure you’ll be seeing the toenails soon, then you bend the probe back and you get…the stupid transgastric view again!

Hell and damnation!

Try again. Here’s an example to help guide you. Say you’re in to 50 cm at the teeth. Advance all the way to 60 cm, then anteflex all the way that the handle can go and come back slowly, ever so slowly. You just might get it. Keep in mind that, even in experienced hands, this deep transgastric long-axis view is just not gettable in 30% of patients.

If you ever DO get the damned view, then you can lay your Doppler right across the valve and get a reading. One problem? You would love to get a specific flow at a specific point (which means you want pulsed Doppler) but the flow through the aortic valve is very fast (pulsed Doppler would alias) so you have to go with continuous wave when analyzing the aortic valve. There is range ambiguity then, and if the flow is faster in another spot (say the patient has subaortic stenosis), then you will get the “fastest” signal from the subaortic spot rather than the valve itself.

Test Note

The pulsed wave versus the continuous wave comes up again and again. Make sure each time you understand WHY you use WHICH ONE.

Absolutely cannot, cannot, get the deep transgastric long-axis view? You can get a less-than-perfect but still usable view with the transgastric long axis.

Note that the alignment isn’t as perfect as the true blue deep transgastric long-axis view.

Real World Note

Getting these views and reading a gradient across the aortic valve is no ivory tower exercise. When surgeons do a myomectomy for IHSS or place a new valve that “might be too small,” they really want to know those gradients because it may determine the success or failure of the procedure. Make sure you do a few gradients on routine cases before you “have to” after an aortic valve or interventricular septum procedure.

Nonvalvular Flow Profiles

This was already touched upon in the discussion of mitral valve inflow and diastolic dysfunction, but it bears repeating.

An important nonvalvular flow pattern is pulmonary venous inflow. When you have an ambiguous read on the mitral inflow (is that “normal” E-to-A ratio actually normal, or is it pseudonormal?), then take a look at the pulmonary veins. If they show a blunted S wave, an enlarged D wave, and a large A wave, then that goes along with diastolic dysfunction. The heart is stiff and the atrium is having a hard time pushing blood into the noncompliant ventricle, so the normal inrush during systole is blunted (blunted S wave), more blood rushes forward when the atrium finally does empty (larger D wave), and more blood goes backward into the pulmonary veins during atrial contraction (larger A wave).

Any other nonvalvular profiles that might come in handy?

Yes! Anytime you are wondering about a structure, you can always lay a Doppler across it and see what gives. Especially when you wander up into views of the aorta or other great vessels, you might see a circle or tube and wonder, “Well, what the Sam Hill is that?” If a patient has distorted anatomy (lymphomatous nodes squishing this and that), you can get mixed up with “is that the aorta coming around, or an innominate vein, or what?”. Doppler will at least tell you if you have an arterial or a venous wave pattern.

Remember the tricuspid valve? When that has regurgitant flow (as already mentioned above), then you can always interrogate the hepatic vein. Reversal of flow in the hepatic vein is consistent with severe tricuspid regurgitation.

By that same logic, would it make sense to interrogate the pulmonary veins to look for mitral regurgitation? Yes. Systolic flow reversal in the pulmonary veins is diagnostic for 4-plus mitral regurgitation.

Whip that damned Doppler all over the place, it will tell you all kinds of stuff.

Questions

1. The IVRT is:

    What best describes the following patients? Normal, impaired relation, pseudo-normal, restrictive filling.

2. E/A = 1, PVF S/D = 1.1_______________________________

3. E/A = 1, PVF S/D = 0.9 _______________________________

4. E/A = 2.4, PVF S/D = 0.9_______________________________

5. E/A = 1, IVRT = 99 ms, _______________________________

6. E/A = 1.5, DT = 190 ms, IVRT = 110 ms_________________________

7. PVF S/D = 1.1, PV – Ar = 33 cm/s_______________________________

8. E/A = 2, PVF S/D = 0.9, PV – Ar = 36 cm/s_________________________

9. DT stands for:

Answers

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