CORRESPONDENCE: LETTER TO THE EDITOR
World Trade Center Attack and Cardiac Events: Fact or Fear?
Laurent Fauchier, MD, PhD*,
Axel de Labriolle, MD and
Dominique Babuty, MD, PhD
* Service de Cardiologie B, Centre Hospitalier Universitaire Trousseau, 37044 Tours France (Email: lfau{at}med.univ-tours.fr).
The Journal recently published two studies suggesting a specific increase in the number of ventricular arrhythmias in implantable defibrillator patients in the weeks following the World Trade Center (WTC) attack of September 11, 2001 (9/11), both in patients living near or geographically distant from New York City (1,2). By contrast, another work found that, compared with control years, there was no disproportionate increase in cardiovascular mortality after the terrorist attacks in New York City (3). A major advantage of this latter study is to compare the variation in the occurrence of events in 2001 and in the years since 1997 (an analysis of "the variation of the variations").
We believe interpretation of the results of Steinberg et al. (1) and of Shedd et al. (2) might therefore be doubtful. Similarly, if the investigators had also found that arrhythmic events were more frequent on 9/11 between 9 AM and 12 noon (after the attack) than between 5 AM and 8 AM (before the attack), it would be difficult to make a direct relation between this phenomenon and the attack, because there is a well-known diurnal variation of cardiac events, with more frequent events in the morning hours (4).
Because a circannual variation of malignant ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators has clearly been reported (with a lower number of events in summer than in autumn and winter) (5), we believe the analysis of the variation of events across several years would also be mandatory to conclude that the WTC tragedy was associated with an increased risk of life-threatening ventricular arrhythmias in the general population.
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1. Steinberg JS, Arshad A, Kowalski M, et al. Increased incidence of life-threatening ventricular arrhythmias in implantable defibrillator patients after the World Trade Center attack J Am Coll Cardiol 2004;44:1261-1264.[Abstract/Free Full Text]
2. Shedd OL, Sears Jr. SF, Harvill JL, et al. The World Trade Center attackincreased frequency of defibrillator shocks for ventricular arrhythmias in patients living remotely from New York City. J Am Coll Cardiol 2004;44:1265-1267.[Abstract/Free Full Text]
3. Chi JS, Poole WK, Kandefer SC, Kloner RA. Cardiovascular mortality in New York City after September 11, 2001 Am J Cardiol 2003;92:857-861.[CrossRef][Web of Science][Medline]
4. Williams ES, Zipes DP. The winter’s tale—and toll Am Heart J 2003;146:941-943.[Medline]
5. Muller D, Lampe F, Wegscheider K, Schultheiss HP, Behrens S. Annual distribution of ventricular tachycardias and ventricular fibrillation Am Heart J 2003;146:1061-1065.[CrossRef][Web of Science][Medline]
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