The group reviewed more than 100,000 records of cardiac patients. They found that there was more chance of surgical problems and death with devices that require electrical leads to be attached to two chambers of the heart compared to those that work on one chamber.
Although there are potential theoretical benefits, the higher-risk complex defibrillators have never been shown to result in improved survival or decreased rates of hospitalization, says Varosy, an assistant professor of medicine at the medical school.
"There is no reason for alarm, and it's important to remember that defibrillators of all kinds have clearly-established benefits in terms of reducing mortality among patients at risk for sudden cardiac death," Varosy says. "But this study does suggest that the simpler defibrillators may cause fewer short-term problems, suggesting that the routine use of dual-chamber defibrillators even in the absence of a simultaneous need for a pacemaker should be re-evaluated."
The two-chamber defibrillator is used in about six of 10 surgeries, according to Varosy, director of cardiac electrophysiology at the VA Eastern Colorado Health Care System. The study was published in the Journal of the American College of Cardiology. It examined 104,000 records of cardiac cases from 2006-07.