Reducing ECG Artifact From Left Ventricular Assist Device Electromagnetic Interference

Abstract

Background Left ventricular assist devices (LVADs) generate electromagnetic interference that causes high‐frequency noise artifacts on 12‐lead ECGs. We describe the causes of this interference and potential solutions to aid ECG interpretation in patients with LVAD. Methods and Results Waveform data from ECGs performed before and after LVAD implantation were passed through a fast Fourier transform to identify LVAD‐related changes in the spectral profile. ECGs recorded in 9 patients with HeartMate II, HeartMate 3, and HeartWare LVADs were analyzed to identify the LVAD model‐specific spectral patterns. Waveform data were then passed through digital low‐pass and bandstop filters and redisplayed to evaluate the effect of filtering on LVAD‐related electromagnetic interference. The spectral profile of patients with HeartMate II and HeartMate 3 LVADs demonstrated a prominent signal at the device‐specific frequency of impeller rotation. In patients with the HeartMate 3 LVAD, 2 additional peaks were observed at the frequencies equivalent to the LVAD's artificial pulsatility rotational speeds. Patients with HeartWare devices demonstrated a prominent signal peak at a frequency equal to double their LVAD's set rotational speed. Applying a low‐pass filter to a value below the observed frequency peak from the LVAD significantly improved the waveform tracing and quality of the ECG. Applying a speed‐specific bandstop filter to remove the observed LVAD frequency peak also improved the clarity of the ECG without compromising physiological high‐frequency signal components. Conclusions LVADs create impeller rotational speed‐specific electromagnetic interference that can be ameliorated by application of low‐pass or bandstop filters to improve ECG clarity.

Keywords

• signal processing
• ECG
• left ventricular assist device