Oscar-winning actress Helen Hayes was in good condition after being hospitalized for an irregular heartbeat, and doctors were trying to determine if she suffered a heart attack or only altitude sickness.

Hayes, 87, was flown from the Crested Butte home of her son, actor James MacArthur, to St. Mary's Hospital in Colorado.Doctors were awaiting test results before making a diagnosis.

Crested Butte, at an altitude of 9,000 feet, is about 100 miles east of Grand Junction.

"Miss Hayes was transported by our Air-Life helicopter from her son's home in Crested Butte," hospital nursing supervisor Karen Bennett said.

"She had traveled from sea level, and one thing we are sure of is that she could not tolerate the high altitude," Bennett said.