Any virus can infect heart-muscle cells, but the novel coronavirus appears to have a particularly detrimental effect, which cardiologists are trying to understand. Autopsy studies of very sick coronavirus patients "have shown that about 50% of them have the virus in their hearts," said Dr. April Stempien-Otero, a cardiologist at the UW Medicine Heart Institute.

SARS-CoV-2 binds to a receptor in heart-muscle cells, which are called cardiomyocytes. The resulting inflammation, myocarditis, has been diagnosed in otherwise healthy college athletes who were thought to have recovered from mild or asymptomatic COVID-19 infections. Those discoveries are part of why many college sports seasons have been curtailed or canceled this fall.

"We don't know how much direct infection of COVID is going to affect future cardiovascular disease," Stempien-Otero said, but we do know that anyone who has high blood pressure, diabetes with heart disease, artery disease – that those patients have twice the rate of death from COVID."

Stempien-Otero also described UW Medicine's protocol to test coronavirus-positive patients for myocarditis.