Two major earthquakes, two studies on how traumatic events affect
the heart--and two completely different results? The answer may be a
testament to what the mind can endure once it adapts to a stressful
situation. Or it may hinge on the clock.
At Stanford University's School of Medicine, psychiatrist C. Barr
Taylor, M.D., and colleagues looked at the prevalence of heart attacks
after the 1989 quake that rocked San Francisco. Medical records at five
Bay Area hospitals turned up 16 heart attacks in the week before the
disaster--and only 12 in the seven days following.
Surprising, considering the cardiovascular trauma unleashed by a
quake: Heart rates skyrocket, blood pressure soars, and breathing becomes
labored. "It's as if we gave a stress test to everybody in the Santa
Clara Valley," Taylor says of the quake. "Not to see any demonstrated
increase in heart attacks is remarkable."
But the findings were far more grim following the 1994 Northridge
quake in Los Angeles. Checking 81 coronary care units around L.A., Good
Samaritan Hospital cardiologists Robert A. Kloner, M.D., Ph.D., and
Jonathan Leor, M.D., counted a 35 percent jump in heart attacks the week
after the quake.
Hospitals within 15 miles of the epicenter were particularly likely
to report more cardiac patients. While the physical strain of escaping
the devastation was a factor in some cases, in others emotional stress
was clearly the trigger, Kloner says.
Why the discrepancy between studies? Are San Franciscans simply
more mentally prepared for the Big One--and thus less shocked when a
quake hits? Support for this idea comes courtesy of Israeli researchers
who looked at Iraq's missile strikes on Israel during the 1991 Gulf
War.
On the day of the first attack, deaths throughout Israel rose by 58
percent, mostly from cardiac-related causes. But in subsequent attacks
there was no rise in mortality, suggesting most people adapted to higher
levels of stress and fear once they knew more missile strikes were
likely.
But Kloner has a different take on the L.A. quake's high coronary
toll: It struck at 4 A.M. "Being awakened from a sound sleep," he
contends, "is very different from already being up and about." Add to
that the physiological reality that heart attacks are already most common
around dawn and the killing potential of an early morning quake takes on
power that doesn't show up on Mr. Richter's scale.
Tags:
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emotional stress,
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israeli researchers,
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trauma,
traumatic events
