Dr. Steven Polevoi, medical director at the emergency department of the University of California, San Francisco, said people tend to delay medical care around the holidays.
"They may have symptoms of cardiovascular disease such as abdominal or chest discomfort which they interpret as indigestion or overeating, but in fact it could be cardiac ischemia -- heavy sensation or pressure on the chest," Polevoi said in a statement.
Cardiac ischemia -- which could lead to a heart attack -- occurs when blood flow and oxygen to the heart are dramatically reduced by narrowing of the coronary arteries.
"You meet the patient and they tell you their story," Polevoi said. "You say, 'Why didn't you come sooner?' and they say, 'Well, I was traveling,' or 'I was having a party.' These can be subtle symptoms patients interpret as something other than a serious condition."
During the holidays people eat more salt and fat, Dr. Ameya Kulkarni, a cardiology fellow, added.
"However, those with heart failure -- for whom the slight increase in salt intake could result in big problems," Kulkarni said.
"And if your heart is already working hard to get oxygen because of narrowing of coronary arteries, then stress will tax your heart, and that demand for more oxygen could cause ischemia or even a heart attack."