A new device that can keep your heartbeat in control

A new device that can keep your heartbeat in control

The 12,000-pound Subcutaneous Implantable Defibrillator, or S-ICD, which is implanted under the skin, delivers a shock if the rhythm of the heart is disturbed and get it back to the regular beat. The battery-operated defibrillator, according to its developers, has been a major success in clinical trials among people who suffered from life-threatening disturbances to their heartbeat -- known as arrythmia, which claims 70,000 lives every year alone in Britain.

Dr Andrew Grace, consultant cardiologist at Papworth Hospital, Cambridge, who helped develop and test S-ICD, said it was a major advance. "This could completely change the use of implantable defibrillators," Grace was quoted as saying by the Daily Mail.

"At present the potential complications are a barrier. Some patients turn them down, and some of them do die as a result of rhythm disturbances that could have been detected and treated with an internal device." The researchers said that the new system delivers a bigger kick-start to the heart than conventional devices in response to life-threatening rhythm disturbances.

And it also offers new hope to sufferers as previous devices had the risk of complications from infection from the leads which connect them to the heart, they said. The new S-ICD system has just one wire going across the chest under the skin, connected to the device implanted beneath the skin on the side which contains the electronic components to deliver the shock.

The added distance from the heart means a more powerful shock can be delivered than from conventional devices -- about 2.5 times stronger. It also means the S-ICD is less likely to pick up electrical noise from the heart which can trigger unnecessary shocks, known as false positives, which can be 'traumatising' for patients, the researches added.

Conventional ICDs require placement of at least one lead in the heart -- usually threaded through a vein -- which sense dangerous changes in heart rhythm and deliver a lifesaving shock. But the leads on these devices are "highly likely" to cause infections in patients who then need treatment or even further surgery to remove them, said Dr Grace.

"This deters some patients from having them implanted, and may mean doctors are less willing to recommend them" he added. The clinical trial data shows the S-ICD is as effective as conventional devices at delivering electrical impulses to restore normal rhythm in almost all episodes of induced disturbances.

The S-ICD also successfully detected all 12 episodes of ventricular tachyarrhythmia in 55 patients using it in a "real-life" trial. Made by US-based Cameron Health, the S-ICD lasts around five years before replacement is necessary.

Dr Grace has started using S-ICD for patients at high risk, including young people with a family history of sudden cardiac death. The breakthrough by an international team of researchers has been reported in the prestigious New England Journal of Medicine.