(Dec 5) WASHINGTON - 'TIS the season to be worried: As people prepare to eat, drink and be merry over the Christmas period, health professionals are getting set for a surge in heart attacks.

Rich food, extra alcohol and seasonal stress make December and January the deadliest months for heart attacks in the United States, and the situation is made even worse by a double dose of denial.

It is not uncommon for people to initially shrug off chest pain as indigestion. Research shows they are also more reluctant to rush to hospital if it means disrupting a holiday gathering or if they are in a city they do not live in.

A 2004 study confirmed the seasonal upswing in heart attacks was a US-wide phenomenon, with peaks in death around the Christmas and New Year holidays.

Vanderbilt University cardiologist Keith Churchwell said a 'hurricane of factors' can tip someone at risk of a heart attack over the edge at this hectic time of year.

Among the dangers are revellers skipping their medications or forgetting them. Many people put on weight, and a particularly heavy and high-fat meal places immediate stress on the heart as it is digested. Blood pressure and heart rate increase.

If a round of parties leaves one tipsy, it also makes the heart pump harder.

Worse is 'holiday heart syndrome', where alcohol irritates the heart muscle, triggering an irregular heartbeat that can can cause a stroke.

People also say they are too busy to exercise, and hospitals may be short-staffed, increasing the time it takes to treat a heart attack victim.