Washington, Sep 24 (IANS): Researchers in the US have found that Covid-19 can leave some patients with signs of heart inflammation and injury months after they get sick with the virus, even in non-severe cases.

The findings could help explain the symptoms of recovered Covid-19 patients, some of whom are struggling with such issues as shortness of breath, chest pain and heart palpitations, according to The Wall Street Journal (WSJ).

"We basically die with the heart-muscle cells we're born with, so anything that results in the death of heart muscle has the potential to irreversibly damage the heart's mechanical ability and the heart's electrical function," Charles Murry, director of the University of Washington's Center for Cardiovascular Biology, was quoted as saying to WSJ.

According to the study, heart inflammation can follow cases of seasonal flu or other respiratory viruses and lead to irregular heartbeats or even heart failure in some cases.

The mounting evidence of Covid-19's toll on the heart stems from studies probing the effect of the coronavirus on heart-muscle cells, and autopsying people who died from the disease, as well as looking at the hearts of patients who have recovered.

The researchers said that the findings are still preliminary, especially those gleaned from testing in lab-grown cells.

"More research, including studies in patients, needs to be done before scientists can reach any conclusions," they wrote.

The research team suspected there are two ways the coronavirus could cause heart inflammation and injure heart muscle.

According to the study, one possibility is that the heart becomes collateral damage in a patient's intense immune reaction to the virus.

The other suspicion is that the virus invades heart tissue, which contains the molecular parts known as ACE2 receptors that the virus uses to enter cells.

The researchers found that the coronavirus could infect and replicate in lab-grown heart-muscle cells, impairing their ability to contract and to conduct the electrical signals required for regulating heartbeat, eventually killing them.

They reported their findings in a paper that was posted in August on a preprint server, but it hasn't been peer-reviewed yet.

Earlier this month another study presented at the European Respiratory Society International Congress, revealed that Covid-19 patients can suffer long-term lung and heart damage but, for many, this tends to improve over time.