A 21-year-old woman in Daegu, South Korea, was the first case of a heart disease linked to COVID-19 – the young woman had noprior medical conditions but suffered an acute myocarditis (inflammation of the heart muscle) and had to be taken to the intensive care unit of a coronavirus-only hospital for critically-ill patients in Daegu. She was hospitalised for a month; a fourth of which was spent in intensive care.

According to cardiologist Dr. Kim In-cheol, who treated the patient, MRI, X-ray and CT imaging of her chest showed obvious signs of infections in the lungs and the heart: “Her chest scans revealed an enlarged heart and patterns of viral pneumonia.”

Her heart had enlarged to nearly 65%,Kim said, explaining the disproportionate cardiothoracic ratio meant the heart’s ability to pump blood had been compromised. A healthy person’s cardiac (heart) size would normally be less than 50% of the thorax (chest cavity).

Although the young woman has since recovered, the extent of cardiac damage from the virus may prove lasting, Kim said.

In the same hospital in Daegu, Korea’s worst affected city with 64%of the total virus tally, close to half of COVID-19 patients have demonstrated signs of heart damage. The fatality rate was also higher for patients who developed heart issues.

“People with heart conditions are at increased risk of a severe COVID-19 infection,” Kim admitted.

As to how infection with the novel coronavirus, SARS-CoV-2, could provoke heart injury, Kim said low oxygen levels in the blood, or hypoxia, is likely diminish the lung capacity for trading carbon dioxide for oxygen, leading to heart muscle injury.

Otherwise, an extreme immune response, known as a cytokine storm, may end up damaging healthy tissue including those in the heart; or, the coronavirus could simply attack the heart muscle by binding to ACE2 receptors in heart cells. The ACE2 entry receptors are found in the lungs, the kidneys, gastrointestinal tract and heart, which is why the coronavirus can easily cause inflammation in organs other than the lungs.

“In the worst of cases, a patient dies from multi-organ system failure after developing pneumonia, heart, kidney, and gastrointestinal problems,” said infectious disease specialist Dr. Kim Woo-joo of Korea University Hospital in southern Seoul.

Another infectious disease specialist, Dr. Kim Tae Hyong of Soonchunhyang University Hospital in central Seoul, said the virus “does not discriminate based on age” and added that the discovery was not revolutionary, as“respiratory viruses such as the influenza have been known to induce cardiac issues in patients.”