Sept. 10, 2004 -- The terrorist attacks of Sept. 11 had a potentially life-threatening effect on some heart patients in New York and Florida, according to two new studies.
All of the people in both studies had implantable cardioverter-defibrillators (ICDs). These implantable devices deliver low electrical pulses, which either stimulate the heart to beat if it has become too slow or interrupt certain types of abnormally fast heart rhythms called ventricular arrhythmias.
The two studies had similar findings, showing a more than twofold increase in abnormal and dangerous heart rhythms of the lower pumping chambers of the heart in the month following the attacks.
Most participants in both studies were elderly men with coronary artery disease who came in for a scheduled visit, not emergencies.
New York Study
Data from 200 New York-area ICD patients was examined by researchers including Jonathan Steinberg, MD, FACC, of St. Luke's-Roosevelt Hospital Center and Columbia University College of Physicians and Surgeons.
ICDs store months of information, providing insight on the patients' hearts before and after 9/11.
In the 30 days following the 9/11 attacks, 16 patients had abnormally fast heart rates, which can cause the heart to pump less efficiently.
That's a 2.3-fold increase in risk compared with the 30 days before 9/11.
The problems didn't start right away.
"The first arrhythmic event did not occur for three days following 9/11," write the researchers in the Sept. 15 issue of the Journal of the American College of Cardiology.
Florida researchers saw the same spike in post-9/11 arrhythmias.
With colleagues, researcher Omer Shedd, MD, of the University of Florida and the Malcolm Randall Veterans Affairs Medical Center in Gainesville, Fla., analyzed data from 132 patients with ICDs.
Shedd's team scanned the devices' information from the 30 days before and after the 9/11 attacks.
Their findings mirrored those of Steinberg's group.
Of the Florida ICD patients, 14 had arrhythmias in the 30 days after the terrorist attacks.
"This represents a 2.8-fold risk increase," compared to the 30 days before 9/11, write the researchers in the same issue of the Journal of the American College of Cardiology.
Stress Defies Geography
The results suggest that distance from ground zero wasn't much protection from arrhythmias.
The Floridians, a thousand miles away from the World Trade Center, had a similar jump in arrhythmia risk as their New York peers.
"A major national tragedy may cause a widespread increase risk of potentially life-threatening ventricular arrhythmias," write Shedd and colleagues.
The reason may be stress from viewing constant media coverage of 9/11 and worrying about future terrorist attacks, say the researchers.
"I think this says a lot about the power of our media," says Shedd in a news release.
"When events such as 9/11 are brought into our homes by television, the Internet, or newspapers, people are clearly moved by what they are seeing, and they physically share in the experience just as if they were near the event."
However, since both studies' participants already had heart problems, the results don't address post-9/11 heart risks for healthy people.