One evening in 1994, I stopped breathing while watching TV. Fortunately my husband Pete, a firefighter, had not gone to rugby training that evening and resuscitated me. It was a very frightening experience. After a battery of tests I was told I had cardiomyopathy, an inherited heart muscle disorder. There are various types but mine, which is called ARVC (arrhythmogenic right ventricular cardiomyopathy), meant that damaged heart muscle was gradually replaced by scar tissue and fat. A recognised cause of sudden death in the young, ARVC also causes weakening of the heart's pumping action.

I had been very fit and healthy throughout my 31 years - or so I thought - but I began experiencing palpitations, light-headedness and extreme tiredness. Initially, I was treated with medication and told not to take part in vigorous sport. Gradually I improved, became pretty much symptom-free, and was able to come off my medication and resume a normal life. I went on to have two children. Apart from regular checkups, I almost forgot I had a problem.

Then in 2002, I suffered a cardiac arrest in my sleep. My breathing became very laboured and noisy, and woke Pete. Once again he resuscitated me. I was now considered at high risk of sudden death and told I should have an internal cardiac defibrillator (ICD) implanted in my chest wall. This is a specialised pacemaker that not only senses and corrects my irregular heartbeat, but also shocks my heart if it develops a life-threatening rhythm. It has two main components: the pulse generator (like a small computer that runs on a battery) and leads that are connected to the heart. It monitors all the time for an abnormal rhythm. If one is sensed, it determines what type of treatment is needed, either pacing my heart or giving it a controlled electric shock. Pacing feels like a fluttering in the chest; a shock is like a strong thump.

The procedure was done under a local anaesthetic with sedation. I went home the following day, and for the first week had to take care not to lift my arms above shoulder height to allow the leads to imbed. The scar is very small and neat, and I have a small bump where the ICD sits beneath the skin near the collarbone.

Physically, my recovery was unremarkable. However, psychologically and emotionally it was much harder. I became very aware of my heartbeat and lived in fear of my device shocking me. I felt very unwell, was unable to sleep, and thought life would never be normal again. I knew I should be grateful for the device and that it should give me reassurance, but that was a long time coming.

A few weeks after the ICD was fitted, I received my first shock. I was walking along the road feeling fine and suddenly came over very dizzy. As the device fired, I felt as if I'd been kicked in the chest by a horse. And while it wasn't what I'd class as painful, it was unpleasant and upsetting. I have had three more shocks since but with these I have lost consciousness and have therefore not felt them. For me losing consciousness is more scary than feeling the shock.

I am now back on medication and have not had any shocks for two years. I have checkups every few months and know that I will have to have the pulse generator replaced at some point as the battery life is normally four to eight years.

My ICD has built-in features that protect it from interference from most electrical appliances. However, it is sensitive to strong electrical or magnetic fields. Therefore I hold my mobile phone on the opposite side of my body to the ICD and do not linger in shop doorways where they have anti-theft surveillance. At airports I do not go through the security archway or have the handheld wand used on me (I have an ID card that I show to security staff).

I lead a full and busy life, and while I have been advised not to take part in competitive or combat sports, I continue going to the gym, skiing and travelling. I recently became a trustee of the Cardiomyopathy Association. The biggest headache for me and my family is that after I've had a shock, I'm not allowed to drive for a minimum of six months. I have now learned to live in harmony with my ICD and not in fear of it. It literally saves my life and I am very lucky to have it.

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