Cardiology MCQ – Impella device – Answer
Contraindication for placement of an Impella mechanical cardiac support device:
Correct answer: 4. All of the above
Impella is a percutaneous transvalvular continuous-flow microaxial pump which is used as temporary left ventricular assist device. Now devices for the right ventricle are also available (when both together are used, some call it Bipella!). Impella 2.5 delivers 2.5 l/min cardiac output while Impella CP delivers 3.5 l/min. It draws blood from the left ventricle and delivers it into the aorta. Hence it will unload the left ventricle, reducing diastolic volume and area of the pressure volume loop or cardiac work. Impella 2.5 needs a 13 F sheath and Impella CP needs 14 F sheath in the femoral artery. Impella is sometimes used in conjunction with ECMO (extracorporeal membrane oxygenator) to vent the left ventricle as ECMO has tendency to increase the left ventricular afterload (some call the combination as Ecpella!).
When there is significant aortic stenosis, it will be difficult to place the device in the left ventricle. In aortic regurgitation, the output delivered by the device will go back into the left ventricle. Left ventricular thrombus is likely to break away and embolize while the device is being placed in the left ventricle.
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- Rab T, Ratanapo S, Kern KB, Basir MB, McDaniel M, Meraj P, King SB 3rd, O’Neill W. Cardiac Shock Care Centers: JACC Review Topic of the Week. J Am Coll Cardiol. 2018 Oct 16;72(16):1972-1980.