TO SLEEP, PERCHANCE TO DREAM . . . AH, HERE'S THE RUB: HEART ATTACK RISK

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

DATE: THURSDAY, February 4, 1993                   TAG: 9302040156
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A3   EDITION: METRO 
SOURCE: Associated Press
DATELINE: BOSTON                                LENGTH: Medium
TO SLEEP, PERCHANCE TO DREAM . . . AH, HERE'S THE RUB: HEART ATTACK RISK
Now it looks like even dreaming may be hazardous to your health.
A new study has found that the periods of sleep when dreams occur kick the body into high gear. The heart speeds up. The blood pressure climbs. And stress hormones prepare the body to run or fight.
Researchers believe all this internal turmoil, which happens while the sleeper is tucked in bed, may trigger heart attacks.
Their study found that during dream sleep, the sympathetic nervous system, which helps the body prepare for emergencies, cranks up in a surprisingly powerful way. In fact, they found, it is twice as active as is normal when people are awake.
"Even at 4 in the morning when you think the body should be fast asleep and quiet, everything is pounding away. The sympathetic nervous system is in overdrive," said Dr. Virend K. Somers of the University of Iowa.
The idea that dreams may be bad for the heart remains highly speculative, but researchers say it makes sense.
Doctors have long noticed that angina attacks, which occur when the heart fails to get enough oxygen, sometimes happen during sleep. Furthermore, people dream the most just before they wake up. And this might help explain why heart attacks are more common in the morning than any other time of day.
Even if dreaming does prove to be bad for weak hearts, there may not be a lot anyone can do about it.
"But maybe we can protect the heart from the sympathetic nervous system activation that occurs during dream sleep," said Somers, who directed the study.
One way to protect people who have heart trouble is with beta blockers. These widely used drugs blunt the effects of stress hormones on the heart. While generally considered safe, they can have side effects, including reducing people's capacity for strong exercise and worsening lung diseases.
Somers' study, published in today's New England Journal of Medicine, was conducted on eight healthy volunteers. While the volunteers slept, researchers measured heart rates, blood pressures and the activation of the sympathetic nervous systems.
They found that during most stages of sleep, the heart rate and blood pressure fell and the sympathetic nervous system grew less active. The exception was during rapid eye movement sleep, the stage when dreams occur.
During REM sleep, the heart rate and blood pressure rose to the level seen during waking hours. And the sympathetic nervous system spurted to twice the state normal during the day, they found.
REM sleep accounts for about one-fifth of sleep time and comes and goes during the night. However, periods of REM sleep are longest just before people awaken.
Somers said people may suffer heart attacks just before they awaken but do not become aware of them until they get out of bed.

by Archana Subramaniam by CNB