Many patients who die of COVID-19 show signs of heart damage, and some of those are dying of heart failure and cardiac arrest even when they aren't suffering from the respiratory symptoms more commonly associated with the novel coronavirus, Kaiser Health News reported.

Doctors observing this trend are now concerned about what this could mean for how the coronavirus is treated, and how it might impact the way they respond to patients who come in with heart failure who haven't been tested for the coronavirus.

Some doctors have found that COVID-19 can create the false appearance of a heart attack:

That work has already resulted in changes in the way hospitals deal with the cardiac implications of COVID-19. Doctors have found that the infection can mimic a heart attack. They have taken patients to the cardiac catheterization lab to clear a suspected blockage, only to find the patient wasn't really experiencing a heart attack but had COVID-19.

That finding could change the way heart attack patients are evaluated:

"We're taking a step back from that now and thinking about having patients brought to the emergency department so they can get evaluated briefly, so that we could determine: Is this somebody who's really at high risk for COVID-19?" said Dr. Sahil Parikh, an interventional cardiologist at Columbia University Irving Medical Center in New York City, according to KHN. "And is this manifestation that we're calling a heart attack really a heart attack?"

Still there are questions about whether COVID-19 is causing heart damage and cardiac arrest by infecting the heart, or whether the heart issues are a byproduct that is occurring when patients become seriously ill. Any serious medical event has the potential to stress the heart to the point of damaging it, KHN reported.

Heart damage has been found in nearly 20% of coronavirus patients, according to one initial study. This damage has shown up in patients with no previous heart illness.

"We have to assume, maybe, that the virus affects the heart directly," said Dr. Ulrich Jorde, the head of heart failure, cardiac transplantation and mechanical circulatory support for the Montefiore Health System in New York City, according to KHN. "But it's essential to find out."