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Effect of the September 11, 2001 terrorist attack on a state highway patrol trooper's heart rate variability
Michael Riediker1, Margaret C Herbst, Robert B Devlin
1Center for Environmental Medicine, Asthma and Lung Biology School of Medicine, University of North Carolina, Chapel Hill, NC, USA. michael.riediker@alumni.ethz.ch
Background:
On September 11, 2001, terrorists attacked the United States. By coincidence, a North Carolina highway patrol trooper was wearing an ambulatory ECG Holter monitor at this time as part of an air pollution study.
Methods:
Heart rate variability parameters were analyzed: standard deviation of normal to normal beat intervals (SDNN) and percentage of interval differences >50 ms (PNN50).
Results:
The trooper's heart rate variability changed immediately after learning about the terrorist attacks. Heart rate increased and PNN50 decreased, while SDNN increased strongly.
Conclusions:
These changes suggest strong emotional sympathetic stress associated with parasympathetic withdrawal in response to the news about the terrorist attack.
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