Shrinking waveforms on electrocardiograms may serve as an indicator of which hospitalized COVID-19 and flu patients are at risk of declining health or death, according to findings published Sept. 25 in American Journal of Cardiology.
Researchers from New York City-based Mount Sinai Health System conducted a retrospective EKG analysis from 140 COVID-19 patients who were hospitalized at the health system between March 7 and April 12, 2020. They compared them with the EKGs from 281 influenza patients admitted to Mount Sinai Hospital between 2017-20.
They analyzed three separate EKG time points for each patient: a baseline scan done within a year before their COVID or flu hospitalization, at hospital admission, and a follow-up EKG during hospitalization. Researchers manually measured QRS waveform height — a measure of electrical activity in the ventricles — on each EKG. Changes in this activity often serve as a sign of failing ventricles.
They then analyzed the EKGs performed during hospital admission for shrinking electrical signals based on a set of criteria they developed called LoQRS amplitude.
The findings showed that of 52 COVID-19 patients who died, 74 percent had LoQRS, or shrinking waveforms, with the waveforms becoming smaller about five days into their hospital admission. Among 281 flu patients, 17 died, with LoQRS present in 39 percent of those cases.
"Our study shows diminished waveforms on EKGs over the course of COVID-19 illness can be an important tool for healthcare workers caring for these patients, allowing them to catch rapid clinical changes over their hospital stay and intervene more quickly," said Joshua Lampert, MD, senior study author and a cardiac electrophysiology fellow at Mount Sinai Hospital.
"This is particularly useful in overwhelmed systems, as there is no wait for blood work to return and this test can be performed by the majority of healthcare personnel."
To view the full report, including how the LoQRS amplitude was defined, click here.