Color Doppler Artifact Masking Iatrogenic Aortic Valve Injury Related to an Impella Device

Abstract

The Impella (Abiomed, Danvers, MA) is a minimally invasive transvalvular left ventricular assist device (LVAD) that effectively unloads the left ventricle (LV), especially in patients with ventricular arrhythmias in the setting of a venous-arterial extracorporeal membrane oxygenator (VA ECMO). 1,2 Utilization of the Impella device has increased significantly in the last few years for high-risk percutaneous coronary intervention and cardiogenic shock because of its relatively easy implantation in the catheterization lab and the operating room. Although rare, iatrogenic injury of the aortic valve (AV) can be caused by placement of the device across the AV.3 This can lead to aortic regurgitation (AR) with significant clinical consequences in the setting of cardiogenic shock. This AR can be challenging to diagnose echocardiographically because of the artifacts generated by the device when using color-flow Doppler. In this E-challenge, the authors emphasize the importance of recognizing these findings for accurate interpretation of the echocardiogram in the management of cardiogenic shock refractory to the Impella LVAD and the utility of transesophageal echocardiography (TEE).

Aortic Valve Leaflet Disruption: A Severe Complication of Impella 5.5

“…While the Impella 5.5 is an integral tool in the armamentarium of heart teams caring for patients with cardiogenic shock, it is not without its pitfalls. Hong and Naseem describe mild to moderate malcoaptation of the aortic valve leaflets, identified while the Impella is in place or shortly after removal [4]. However, it is believed to be short-lived [4].…”

The Mitral/Aortic Flow Velocity Integral Ratio in Mitral Regurgitation

“…[15][16][17][18][19][20] Recent literature highlights the overestimation of mitral regurgitant severity with color flow Doppler compared with magnetic resonance imaging, the new gold standard. 21,22 The updated American Society of Echocardiography guideline document now explicitly states that color flow Doppler vena contracta is not the actual vena contracta. 3 Given the limitations of ultrasound physics, color flow Doppler does not accurately represent the dynamic details of in vivo cardiac hydraulics but provides only a rough approximation of intracardiac blood flow.…”

“…[23][24][25] Care must be taken when imaging prosthetic valves, patients with severe annular calcification, or patients with ventricular assist devices. 22,26 The authors' 2 cases highlight the setting where severe annular calcification appears to have attenuated the color Doppler signal. The absence of a color flow Doppler image does not equate to the absence of regurgitation.…”

A case of cardiogenic shock due to acute coronary syndrome successfully recovered by percutaneous and paracorporeal left ventricular assist device

“…A case of acute MR due to chordal rupture and flail mitral valve leaflet was reported during Impella replacement [17]. Impella could also cause an iatrogenic injury of the aortic valve [18]. In this case, already existing mild AR in the native valve might be worsened to moderate by the insertion of Impella or blood supply by Nipro-VAD into ascending aorta, which eventually required the valve replacement at the time of VAD explantation.…”