Defibrillator Shock Linked to Early DeathSep 4, 2008 | Parker Waichman LLP
While a defibrillator shock may provide a lifesaving nudge, the Associated Press reports that such a shock from an implanted heart defibrillator may also be linked to future problems and early death. The government-funded study revealed that heart failure patients were far more likely to die within four years following defibrillator activity than patients who were not shocked.
Experts urge patients to immediately advise their doctors if they experience defibrillator triggering. Likewise, doctors are urged to review their patients' condition to determine if the condition has worsened and if tests or medication changes are required. "We need to think about everything else we possibly could do to make them as healthy as they can be," said the study's lead author, Dr. Jeanne Poole of the University of Washington. The study’s findings appear in today's New England Journal of Medicine.
Approximately 234,800 North Americans have been implanted with defibrillators at a cost of about $25,000-$35,000 each. Defibrillators are about the “size of a stopwatch and designed to correct dangerously high or erratic heartbeats in the lower, pumping chambers of the heart,” said the AP. Earlier research determined that defibrillators cut the risk of death by nearly one-quarter. This new study is derived from that same study of 2,500 heart failure patient. In those earlier cases, patients’ weakened hearts were not pumping efficiently, but patients had not yet experienced a life-threatening irregular heartbeat. This means that although the risk of death was cut by nearly 25 percent, the patients studied did not receive a defibrillator shock.
Although the new report indicates that a defibrillator prolongs "survival in patients with heart failure, with relatively little compromise in the quality of life," wrote Drs. Jeff Healey and Stuart Connolly of McMaster University in Hamilton, Ontario, in a journal editorial, the doctors did add, "It is somewhat disturbing to realize that actually receiving a shock is such an important predictor of death." The study found that approximately one-third of the 811 patients implanted with defibrillators received a shock in about four years of follow-up.
The devices’ recorded data indicates if the shock corrected a life-threatening irregularity or was inappropriately fired by another problem, such as an abnormal rhythm in the heart's upper chambers. The research revealed that patients who needed a shock were five times more likely to die over the next four years than those who didn't require one. Those who did not appear to need a shock but who were shocked, experienced double the risk of dying.
Medtronic Inc. provided the defibrillators used in the research and Wyeth provided the medicine. Many of the researchers and the editorial writers received lecture fees or grants from defibrillator makers. Medtronic defibrillators have been involved in a recalls for problems with faulty leads that could fracture within a patient’s blood vessel, delivering a massive electrical jolt that could result in extreme pain or even death, including at least five such deaths. Problems with Medtronic devices were linked to at least four deaths and one injury because of the devices not charging properly, resulting in late or no delivery of cardiac shock therapy.