- Kevin M. Rice, MD
Impella Left Ventricular Assist Device
Updated: Jul 27, 2021
Name the Device • Xray of the Week
CXR for CHF. Name the cardiac device and what the 2 images have in common.
Fig. 1. Chest X-ray with arrows pointing to the Impella® Heart Pump. Archimedes’ screw.
Fig. 2. Arrows pointing to an Impella® Heart Pump. Blue arrow- outflow area, red arrow- inflow area, green arrow- distal pigtail.
Fig. 3 Video explaining percutaneous placement technique for the Impella® Heart Pump.
Fig 4. Automated Impella® Controller.
Discussion:
The Impella 2.5® heart pump is a catheter-mounted pump that works on the principle of Archimedes’ screw (Figs.1-5). It is used to temporarily assist the pumping function of the heart during high-risk percutaneous coronary interventions (PCI) to ensure blood flow is maintained to critical organs in patients with severe coronary artery disease. The device may also be used to temporally treat ongoing cardiogenic shock that occurs immediately following acute myocardial infarction or open heart surgery or in the setting of cardiomyopathy.
The Impella 2.5 pump is inserted percutaneously through the femoral artery, into the ascending aorta, across the aortic valve and into the left ventricle (Fig.3). The Impella (Fig.2) then pulls blood from the left ventricle through an inlet area near the tip and expels blood from the catheter into the ascending aorta at a maximum rate of 2.5 L/min. The external Automated Impella® Controller (Fig.4) controls the Impella catheter performance, monitors for alarms, and displays real-time hemodynamic and catheter position information.
On radiographs, the distal tip of the catheter has a pigtail configuration and is positioned in the left ventricle. The blood inlet and outlet areas are metallic radiopaque and are visualized in the left ventricle and ascending aorta respectively (Fig.2).
Fig 5. Archimedes’ screw. The water screw, popularly known as the Archimedes' screw and also known as the screw pump, Archimedean screw, or Egyptian screw, is a machine used for transferring water from a low-lying body of water into irrigation ditches. Water is pumped by turning a screw-shaped surface inside a pipe. Wikipedia
References:
1. Abiomed website: https://www.impella.com/how-the-impella-heart-pump-works
2. Wikipedia- Archimedes' screw. https://en.wikipedia.org/wiki/Archimedes'_screw
3. Ginat D, Massey HT, Bhatt S et-al. Imaging of mechanical cardiac assist devices. J Clin Imaging Sci. 2011;1 (1): 21. doi:10.4103/2156-7514.80373
4. Godoy MC, Leitman BS, de Groot PM et-al. Chest radiography in the ICU: Part 2, Evaluation of cardiovascular lines and other devices. AJR Am J Roentgenol. 2012;198 (3): 572-81.
5. Radiopaedia- Impella left ventricular assist device. https://radiopaedia.org/cases/impella-left-ventricular-assist-device?lang=us
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Kevin M. Rice, MD is the president of Global Radiology CME
Dr. Rice is a radiologist with Renaissance Imaging Medical Associates. He has held many leadership positions including Radiology Department Chair and Chief of Staff. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field.
Follow Dr. Rice on Twitter @KevinRiceMD
