Initially, COVID-19 was thought of as primarily a respiratory disease, but scientists have since discovered that it can severely affect the heart and other organs as well. In a new study, scientists at San Francisco-based Gladstone Institutes explore the lasting heart damage caused by COVID-19.
The study, which has not yet been peer-reviewed, shows the virus' effects on the structure of heart cells in the laboratory and in heart tissue taken from COVID-19 patients who died.
The scientists exposed heart cells in lab dishes to varying doses of the new coronavirus. The virus was able to enter heart muscle cells and make new copies of itself. They also observed that in the exposed heart muscle cells, the long muscle fibers called sarcomeres appeared to be diced into smaller fragments.
"The sarcomere disruptions we discovered would make it impossible for the heart muscle cells to beat properly," said Bruce R. Conklin, MD, an investigator at the Gladstone Institutes and a professor of medicine, cellular and molecular pharmacology, and ophthalmology at University of California San Francisco.
Also, the scientists found that nuclear DNA appeared to be missing from many of the heart cells exposed to the virus, without which the heart cells cannot perform any normal functions.
The scientists also examined heart tissue samples from COVID-19 autopsies, which corroborated their findings on structural cell changes in the lab. They found that structural abnormalities in heart muscle cells were evident even among patients who had not been diagnosed with heart disease related to COVID-19.
The scientists also warned that since the heart does not regenerate, it is possible that someone who contracts COVID-19 could recover and develop heart disease years later.