Refining Auscultation of Left Ventricular Assist Devices: Insights From Phonocardiography

Abstract

There have been over 15,000 continuous flow left ventricular assist devices (LVADs) implanted in the United States1 . As the care of these patients expands into the general community, it is important for providers at all levels to be familiar with the sound of a normal LVAD. The sound generated is normally described as an “LVAD hum”. That non-descriptive term may be misunderstood as all LVADs or “hums” are the same, when in fact the sound produced is unique to each device. Another common misconception held by some providers, is the absence of heart sounds in a normally functioning LVAD. Using apex phonocardiography we were able to better visualize these unique characteristics (Figures 1-4, phonocardiograms of three United States Food and Drug Administration approved durable LVADs), and suggest a refined description of each device sound. The recordings were made on normal functioning LVADs using the EKO Core stethoscope attachment (EKO, Berkeley, CA).