“People often don’t realise just what unpleasant and flawed devices standard defibrillators are,” says Andrew Grace, a cardiologist and biochemist at the University of Cambridge and Papworth Hospital, also in Cambridge. For this reason he has been working with Cameron Health of San Clemente, California, to develop a defibrillator that may spell an end to unnecessary shocks by more thoroughly assessing electrical activity in the heart.

Standard defibrillators are connected to the heart via wires, and judge how well the organ is functioning by monitoring the small area of tissue that is usually the origin of rhythm disturbances. However, electrical anomalies in this area are not always mirrored elsewhere in the heart, and are therefore not always significant. But defibrillators still kick in and give the heart an unnecessary shock.

The new device scans the whole heart in the same way as an electrocardiogram (ECG) and will only provide a shock if it picks up a major, organ-wide irregularity. Like an ECG it uses sensor electrodes and magnets to pick up the electric fields generated by electrical activity in the heart muscle.

As well as avoiding false alarms, the device is less invasive than standard defibrillators as it is not attached to the heart itself but fits on the chest just under skin. This makes fitting it simpler and safer.

Cameron Health is hoping to run pan-European human trials in April. The less invasive nature of the device means it may be suitable not only for people who have a history of heart-rhythm disturbances, but also for some of the hundreds of thousands of people who have serious heart attacks each year, and who are at greatly increased risk of sudden death from abnormal heart rhythms.

MEDICA.de; Source: New Scientist