A T-shirt that constantly monitors the heart’s activity and detects abnormalities could help protect people against stroke

A T-shirt that constantly monitors the heart’s activity and detects abnormalities could help protect people against stroke — and may even help diagnose the cause of fainting.

The high-tech shirt, called Cardioskin, has electrodes stitched into the cotton fabric which carry out round-the-clock checks on the heart’s electrical activity. These then connect to a tiny chip in the garment which wirelessly beams the results to an app on the patient’s smartphone.

The app is able to share the data with a cardiologist, who can assess it.

The T-shirt, which can be washed up to 35 times before it needs replacing, has been developed to improve the detection of dangerous heart conditions such as atrial fibrillation, which causes an irregular heart rhythm and raises the risk of stroke.

At least one million people in Britain are known to have this condition, however, the charity Arrhythmia Alliance estimates that  at least another 500,000 have  it but have not yet been diagnosed because they have no obvious symptoms.

The cause is unknown, though high blood pressure, chest infections, an overactive thyroid and too much caffeine or alcohol have all been cited as possible triggers.

It develops when electrical activity in the heart goes haywire. One in 25 people over 60 get it.

Some will have symptoms such as chest pain, dizziness and fatigue; but a significant number have no idea they are ill until they suffer a stroke.

As the heart no longer beats in a regular fashion, blood begins to ‘pool’ and thicken inside the left ventricle — the heart’s main pumping chamber.

If a clot then breaks away and travels up through the narrow blood vessels that feed the brain, it can cause a fatal stroke by blocking the brain’s supply of oxygen-rich blood.

Common treatments for atrial fibrillation include drugs, such as  the blood-thinner warfarin, to  stop clots forming, and cardioversion, where the heart is shocked back into normal rhythm using electrodes. Detecting atrial fibrillation involves carrying out an electrocardiogram (ECG).

Conventional ECGs are done in a hospital and involve highly trained teams of staff attaching up to 24 separate electrodes to different parts of the body to measure electrical signals.

But most patients experience abnormal rhythms only intermittently (some can go days or weeks without an episode).

This means the chance of picking them up during a short hospital check is slim.

Doctors sometimes issue patients with a device called a Holter monitor to wear under their clothes to try to pick up cardiac problems.

This is an electronic box which clips on to your waistband and is connected to a series of electrodes that are worn on the upper part of your body. But the box itself is quite bulky, hard to disguise beneath clothing and it can be uncomfortable, involving a dozen or more wires being attached to the patient’s chest.

As a result, patients often stop wearing it — especially at night when it can make sleep difficult — reducing the chances of a faulty heartbeat being picked up.

The Cardioskin T-shirt, which is  made from a white cotton fabric, could be a much more convenient alternative and can be worn 24 hours a day — meaning it is more likely to pick up any abnormal rhythms in the patient’s heart. It has 15 tiny electrodes woven into the material which are strategically placed around the chest area in order to track the electrical signals from the heart as they travel across the torso.

The electrodes are powered by a battery (which can be removed easily when you need to wash the T-shirt) and feed results to a microchip which then transmits them wirelessly to an app.

This converts the data into an easy-to-read chart showing if the heart rate is abnormal.

The results are shared with the patient’s doctor so they can check the patient’s heart without having to call them into the clinic for an appointment.

As well as atrial fibrillation, the T-shirt can detect other problems linked to faulty heart rhythms such as syncope, which produces frequent episodes of fainting.

The T-shirt, developed by French drugs company Servier, has been approved for sale in the UK and is expected to become available for doctors to use later this year, although the price has not yet been announced.

Martin Cowie, a professor of cardiology at Imperial College London, said: ‘It is fantastic to see a new solution to the very real problem of diagnosing intermittent heart abnormalities that may explain serious conditions such as syncope [fainting] or stroke.’

He told Good Health: ‘Cardioskin could be an important development for cardiologists.’