My sister, Laura and I are own as the "Bionic Babes" in our home town of Southampton, because we both have tiny defibrillators implanted in our chests, designed to constantly monitor our heartbeat, and shock us back to life if it ever stops.

We both have a rare condition that means our hearts can stop if we're startled or suffer from stress.

I'm only 17, but have already "died" five times and had to be revived.

Our dad died when I was eight, and doctors could only tell Mum that it was "sudden death".  He was a fit, healthy man, and his death was totally unexpected.

A few years later Mum saw a documentary about an inherited heart condition that can cause sudden death with no advance warning symptoms.

Diagnosed

She had to fight to have Laura and I tested, as every doctor she spoke to said it was unnecessary.  Eventually one hospital agreed and the tests revealed we both had a rare illness called Long QT Syndrome.

Basically, it involves the electrics in your body "misfiring" and disrupting the signals that control the heartbeat.  Your heart can miss a beat or stop.  There are no warning signals but, potentially, you can just drop dead on the spot.

At the time we were diagnosed, I was only 10 and Laura was six, so we didn't understand just how serious it was but from that day on normal life changed.

Because an attack can be brought on but a shock, over-excitement or exercise - anything that quickens the heart - we had to be very careful.  I couldn't ride my bike, do PE at school, watch scary films or even have an alarm clock.  Waking up in the morning was the most dangerous time because as your heart speeds up naturally, the shock of an alarm clock could have proved fatal.

Worst of all there had to be someone with me everywhere I went, in case I suddenly collapsed - even to the loo!  I hated it and felt trapped.  Even with all the precautions, I still managed to die at least five times.

Once I was punched accidentally at school and collapsed.  Another time my heart stopped when, against the rules, I went on a fairground ride, and it must have been too much for me.  Mum was furious when she found out, but it was so frustrating not being able to do all the things every other young girl could do.  Even going to a disco was forbidden.  Any kind of excitement could trigger my heart to stop.

I've come round in school more than once, with shocked looking teachers and sobbing schoolmates looking down at me.  Luckily my heart always restarted, but there was always the risk that one day it wouldn't.

My sister's condition seems to be less serious than mine.  She's suffered from chest pains, but never collapsed.

Treatment

Then in 2002, doctors suggested that we both have tiny defibrillators implanted in our chests.  They're mini versions of the machines you see on hospital drams, which are used to shock people back to life.

The ones Laura and I have are no bigger than a cigarette lighter, and constantly monitor our hearts for any "flutter".  If the heart stops, they automatically shock it back to life.

We both had the operation on the same day but the worst part was when we were taken back down to theatre a few days later so doctors could stop our hearts to make sure the machines worked - thankful they did!

I've been told that when the machine does go off, it's like being kicked in the chest by a horse.  Luckily it's never had to jump into action for real.

I'm just glad it's there as it gives me reassurance, but I still have to be careful.  I keep my mobile phone away from the implant and even getting too close to stereo speakers could switch it off.

Counselling

Laura and I have also joined CRY - Cardiac Risk in the Young, a support group for young people with cardiac problems.  They helped us come to terms with our illness and, now, we're taking a counselling course to be able to help others like us.

We're supposed to have a rare condition but around eight young people a week die of "sudden death syndrome". 

We're also trying to raise funds for CRY, and let more people know about our illness - thanks to our Mum's much loved VW bus which has been painted pink and touring the country collecting celebrity autographs.  We just collected Ester Rantzan and the Cheeky Girls and their signatures on heart shaped stickers are now on the bus.

Mum was remarried earlier this month and in October she and our step dad will be having an unusual honeymoon - taking the bus from Land's End to John o' Groats.

I've decided life is for living, so I'm going to live it to the full.