Assessing Impella® Heart Pump Position with Echocardiography
Michael Galvin, RDCS, a cardiac sonographer and Abiomed clinical support center specialist, discusses echocardiography for evaluating Impella® position. He explains why echo is the preferred imaging modality for Impella patients and describes how to look at echo images of Impella and understand what you are seeing.
In chapter 1, Mike Galvin answers the questions:
- When should we use echo to assess Impella position?
- What does echo tell us about Impella?
- What do the components of Impella look like under echo?
He explains that proper Impella position is best evaluated using parasternal long-axis echocardiography, which provides the best views of cardiac structures. He shows how to locate the inlet of the Impella heart pump by looking for the bright artifact of the stainless-steel teardrop and the “railroad tracks” of the cannula.
In chapter 2, Mike Galvin describes how to measure Impella position to ensure that the inlet is approximately 3.5 cm from the aortic valve annulus. He explains how this can tell us whether Impella is too deep in the ventricle or too shallow. He also provides a first-hand example of what can happen when a sonographer doesn’t understand how to measure Impella position in the left ventricle.
In chapter 3, Mike presents examples of suboptimal placement of Impella. He shows echo images of the pigtail hooked onto papillary muscle as well as Impella directed posteriorly into mitral valve leaflets, against the posterior wall, and swinging in the left ventricle due to slack in the catheter.
Chapter 4 presents how to use color Doppler to assess the position of Impella. Mike describes the mosaic pattern seen above the level of the aortic valve when Impella is properly positioned. He also explains what you’ll see if Impella is not properly positioned and how to use color Doppler to evaluate position using transesophageal echo.
In chapter 5, Mike discusses using off-axis views and additional windows to evaluate Impella position. While parasternal views are preferred for measuring Impella position, apical 3 and apical 5 chamber views, as well as subcostal views, can provide additional information. He reminds us to consider the patient’s condition—whether we are seeing low flow alarms or hemolysis issues—when looking at echo images. He also reminds us to evaluate right heart function on every echo to determine whether there’s a right heart problem.