Reassurance offered over defibrillators

Fears that modern defibrillators have negative side effects are unfounded, scientists said today.

Patients have in the past complained implantable cardioverter defibrillators (ICDs) increased their anxiety during cardiac arrest, which they are specifically designed to reduce the risk of death from.

An ICD monitors the heartbeat for arrhythmia and delivers a jolt of electricity to restore normal rhythm if needed, with some patients describing the shocks as painful and unsettling.

But a new study from US scientists says patients and physicians can use the ICDs confident they will not lower a person’s quality of life.

The Duke University Medical Centre in North Carolina studied 2,521 cardiac arrest patients enrolled between 1997 and 2001.

One third was randomly assigned to receive ICD treatment, while the rest received either an anti-arrhythmia drug or a placebo.

Participants were then interviewed four times over a 30-month period on disease status, physical and social activity levels, psychological wellbeing and their ability to perform routine daily tasks.

Researchers, publishing their findings in the New England Journal of Medicine, reported that ICD patients had improved wellbeing at three and 12 months, although all participants had evened out by the end of the trial.

“Medical intervention almost always brings about unintended consequences,” said cardiologist and lead author Dr Daniel Mark.

“We are now happy to report that we found no evidence of that in this large trial. ICD users, on the whole, appear satisfied with the benefits and the consequences of defibrillator therapy.”