Using pulmonary regurgitation to infer right-heart pressure in echocardiography

When assessing right ventricle pressure in congenital heart disease, you can leverage the pulmonary artery diastolic pressure. Which view should you use? At which exact point should you measure the pressure of the pulmonary regurgitation jet? In this video, Cristiana Monteiro—a cardiac physiologist from the University of Oxford—provides answers and explains the underlying physics for this procedure.

We too often focus on the left ventricle and its pathologies when performing echo, forgetting that the right heart is also a significant source of symptoms and complications. It is an important prognostic predictor for many cardiac diseases. In this course, we’ll teach you the pearls and pitfalls of right-heart echocardiography so you can confidently assess the right heart and its pathologies. Master right-heart echocardiography and learn how to confidently assess the right heart and its pathologies with this course.

At the end of this Medmastery lesson, you will be able to leverage pulmonary regurgitation when assessing right heart pressures. Namely, the pulmonary artery diastolic pressure. Almost everyone has some degree of pulmonary regurgitation, which can vary from trivial to severe. In order to determine the severity, we can record a spectral trace of the pulmonary regurgitation using continuous wave Doppler.

In this case, we want to measure the end diastolic pressure of the pulmonary regurgitation jet. As opposed to the end systolic pressure we measure to determine the tricuspid regurgitation jets. Here we have an example of a parasternal long axis view of the right ventricular outflow tract. Start by placing your cursor across the pulmonary valve, in the middle of the pulmonary artery, seen here as a dashed line.

If a pulmonary regurgitation jet is visible, it will appear as a predominantly red jet above the pulmoary valve during diastole. You will want to measure the velocity at the end of the pulmonary regurgitation trace, this point will be above horizontal axis just before the normal pulmonary valve jet, which is seen the below your horizontal axis.

This moment in time matches the onset of the QRS wave on the electrocardiogram trace. And as with the tricuspid regurgitation trace, the echo machine will automatically calculate the equivalent pressure. Now for a bit of theory, the pressure of a pulmonary regurgitation jet reflects the pressure difference between the pulmonary artery and the right ventricle in end diastole. Therefore, if we rearrange the equation and add the pressure of the pulmonary regurgitation jets to the right atrial pressure, we can estimate the pulmonary artery diastolic pressure for the PADP.

Although this measurement is not widely used in normal practice, you may need to know how to calculate it in some very specific cases. For instance, in congenital heart disease. You can estimate the right atrial pressure by checking your national echocardiography guidelines for the correct estimation. Once you have, simply add this value to your measured pulmonary regurgitation end diastolic pressure, and report the final result as PADP. Here's an example.

The pulmonary regurgitation jet has a pressure of 4.68 millimeters of mercury with an estimated right atrial pressure of 10 millimeters of mercury. Simply add these values together to calculate a pulmonary artery diastolic pressure of 14.68 millimeters of mercury, which should be rounded up and reported as a PADP of 15 millimeters of mercury. And that's it. Easy, right? You now understand how you can use pulmonary regurgitation, to estimate pulmonary artery diastolic pressure.