Shake and wake – studies of heart attacks related to earthquakes in San Francisco, CA, in 1989 and Northridge, CA in 1994
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 dearly 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 missle 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.
COPYRIGHT 1995 Sussex Publishers, Inc.
COPYRIGHT 2004 Gale Group