Algorithm for improving the clarity of electrocardiograms for patients with LVADs

Unmet Need

Electrocardiogram (ECG) measurements are an important tool for monitoring patient heart health and can detect issues related to arrythmias, heart attacks, and cardiomyopathy. Heart health is especially important to monitor in patients who use mechanical support devices, such as left ventricular assist devices (LVADs). Up to half of patients with LVADs develop arrhythmias, which need to be closely monitored using ECGs. However, LVADs produce electromagnetic energy that interferes with ECGs, making the measurements difficult to interpret and leading to possible misdiagnosis of cardiac issues. LVADs often produce high frequency electromagnetic signals that cause interference on ECGs; however, the heart produces valuable electrical information in this range, so blocking out all high frequency signals is not feasible. There are over 9,000 LVAD implantations annually, and the LVAD market is expected to increase in the coming years due to a steadily ageing population in the US. Therefore, there is a clinical and commercial need to develop signal processing technologies that effectively filter out the interference produced by LVADs to enable the accuracy of ECGs in LVAD patients and easier diagnosis of arrhythmias and other cardiac issues.

Other Applications

This technology can also be applied to remove electromagnetic interference from other medical devices that emit high frequency electromagnetic signals, including deep brain stimulators.

Technology

Physicians at the Duke School of Medicine have created a data processing algorithm intended to improve the clarity of ECGs for patients with LVADs. This technology isolates and removes the specific frequency of LVAD interference which preserves the relevant physiological information from the low and high frequency ranges. Specifically, this excludes a narrow frequency band based on the device-specific interference to preserve the key cardiac body surface potentials.

This algorithm has been tested for its efficacy in patients with several different commercially available LVAD systems and has demonstrated increased clarity of ECG signal.

Advantages

  • Facilitates easier diagnosis of cardiac problems in this vulnerable group by enabling clearer ECG measurements from patients while preserving important biological measurements
  • This algorithm has been successfully validated in patients with several commercially available LVAD systems, including HeartWare, HeartMate II, and HeartMate 3
  • Filters out LVAD interference while preserving biological signals within the same frequency range, which is crucial for monitoring cardiac health without compromising data quality
  • A data post-processing method that can be applied quickly and easily to existing electrocardiogram measurement systems without the purchase of new hardware
Electrocardiogram data from a patient with a mechanical heart support device, specifically a left-ventricular assist device, or LVAD, shows that the LVAD causes interference and noise in the signal. Bottom figure: After applying a filter, the high-frequency noise is reduced and the true signal from the heart is clearer and easier to interpret.
Electrocardiogram data from a patient with a mechanical heart support device, specifically a left-ventricular assist device, or LVAD, shows that the LVAD causes interference and noise in the signal. Bottom figure: After applying a filter, the high-frequency noise is reduced and the true signal from the heart is clearer and easier to interpret.