NEW YORK — Emergency room visits in the U.S. for chest pain and heart attacks fell early this spring, according to a study that supports fears that the coronavirus outbreak scared people away from going to the hospital.

ER visits were up for respiratory illnesses and pneumonia, but were down for nearly every other kind of injury or ailment, the Centers for Disease Control and Prevention reported Wednesday.

Overall, fewer ER patients showed up: Visits were down 42% in a four-week period that stretched from late March through most of April, compared to the same time last year.

At the time, hospitals in some U.S. cities — most notably New York — were overwhelmed treating COVID-19 patients. But the CDC study covers 43 states and saw big declines, particularly in visits involving preteens.

Some of that may be good news — there may have been fewer injuries from some types of accidents, for example, because people were staying at home and not doing as many risky things at work or play.

But some experts worry about the CDC finding 1,100 fewer visits per week for heart attacks, and 24,000 fewer for chest pain.

The finding seems to parallel death certificate reports. In each of the first three weeks of April, the nation saw 2,000 more deaths than normal in a category that is primarily heart attacks.

That may be the result of some patients worrying more about catching the coronavirus at a crowded ER than their heart problems, some experts think.

“There’s a lot of evidence that suggests people are afraid to interact with medical care, and are deciding not to act on their symptoms,” said Wayne Rosamond, a University of North Carolina researcher who studies heart disease and stroke trends.

The CDC report echoes research in the U.S. and Italy, which showed reductions in heart-related hospital admissions and use of labs to clear clogged arteries but no drop in heart attack deaths during coronavirus.

The latest study found a small increase in people arriving at the ER in cardiac arrest — their heart had stopped. One possible explanation: “They could have been people with heart attacks who waited too long,” Dr. Harlan Krumholz, a Yale University cardiologist and health care researcher, said in an email.

“If someone is having acute chest pain and (thinks) they’re having a heart attack, they should call 911,” Rosamond said. “You shouldn’t ignore these things. You should seek help.”