
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: SUNDAY, March 10, 1991                   TAG: 9103100116
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A2   EDITION: METRO 
SOURCE: Associated Press
DATELINE: BOSTON                                LENGTH: Medium

HEART ATTACKS HIT MOST OFTEN AT DAY'S START

Here's something to think about as you climb out of bed in the morning: For the next two hours, your risk of dropping dead from a heart attack is twice as high as it is the rest of the day.

You could, of course, stay in bed. But sooner or later, you'll have to get up for something. And that's when the trouble starts.

Starting the day is risky business. Besides heart attacks, strokes also are more common then.

Blame nature for its strategy of giving the body a kick start in the morning. Experts believe the hazards to the heart almost certainly result from the eruption of internal chemical and mechanical changes that break loose the moment your feet hit floor.

As unsettling as all of this may seem, the discovery of the perils of arising has been a genuine delight to heart specialists. It may help answer one of the most stubborn puzzles of their profession: What exactly triggers a heart attack?

Searching for the underlying cause of the morning spate of heart attacks has become a hot area of medical study, involving perhaps 50 research groups around the country. What makes the scientists so happy is the recognition of a pattern. Until recently, it seemed heart attacks occurred erratically throughout the day.

"This shows that heart attack is not a random phenomenon," said Dr. Richard Lee of Brigham and Women's Hospital in Boston. "Any time that we see something is not random, it means there may be a way to intervene and prevent the problem."

Researchers hope that if they know how stresses on the heart increase in the morning, they will be well on their way to zeroing in on the forces that touch off heart attacks, and that will help them design new ways to prevent them.

"What is it in those first hours that triggers the heart attack?" asks Dr. James Muller of New England Deaconess Hospital in Boston. "If we could figure it out, we think it would apply to other times of the day, as well."

Muller discovered by chance in 1985 that patients participating in a large heart-attack study were stricken more often in the morning.

Most heart attacks begin when plaque - a lump of cholesterol on the wall of an artery - cracks open. A blood clot forms and sticks to the break. This lump bulges out into the artery, choking off the flow of blood to the heart, and a section of heart muscle dies.

The body's built-in preparations to help its owner face the rigors of the day seem to increase the odds of a heart attack in several ways. Perhaps the most important is a waking release of stress hormones, such as adrenalin.

These hormones prod the heart to beat faster, the blood pressure to rise and the arteries to narrow. Experts believe these sudden changes put physical stress on plaque and increase the odds that some will crack and break.

by CNB