I was lucky to find out before it was too late

LAST summer, my heart started to feel as though it was skipping beats. It was as if I’d been winded, and if it happened a few times in a row, I felt momentarily light-headed.

In August, an exercise test (where you run on a treadmill while electrophysiologists measure what’s happening inside your heart) revealed that this funny sensation was dangerously fast heartbeats — a condition called non-sustained ventricular tachycardia.

Although alarming, it wasn’t entirely unexpected. Ten years before, my GP had referred me to a cardiac physician after finding my blood pressure was worryingly high.

At the hospital, an ECG and echocardiogram (an ultrasound of the heart) found — by chance and unrelated to my raised blood pressure — that I had hypertrophic cardiomyopathy (HCM), the condition that Sir David Frost and his son Miles both had.

At 2cm, my heart wall is twice as thick as a healthy heart muscle. The thicker it becomes, the harder it is for my heart to pump blood.

I left the hospital in shock. Although one in 500 people have the condition, I’d never heard of it. And most articles mentioned Sudden Arrhythmic Death Syndrome, which did nothing to calm my anxiety.

For some, HCM causes breathlessness or fainting. In rare cases, it can kill. But most people have no symptoms and the condition never worsens. I’m the only person in my immediate family known to have it, and thankfully doctors were satisfied that a healthy lifestyle, regular check-ups and a low-dose beta-blocker would control it. As the years passed, I hardly thought about my heart. And then came the funny beats.

I learned that these can be a sign your heart isn’t working properly. The heart’s abnormal thickness may be affecting its electrical signals, or it may be due to scar tissue (a by-product of the thickening).

Either way, I was at increased risk of sudden cardiac arrest. My risk of premature death was estimated to be just less than 6 per cent — about one in 17.

There was no getting away from the numbers. The odds were too high for a 36-year-old woman. To cut my risk, I’d need an implantable cardioverter-defibrillator (ICD) in my chest. This palm-sized device has wires running into the heart through a vein to monitor your heartbeat and deliver a shock if you are in danger of cardiac arrest.

In one in ten patients, the device goes off unnecessarily. Apparently it’s like being kicked in the chest by a horse and hit over the head with a cricket bat simultaneously.

But there was no other option. And so, a few weeks later, I awoke with an ICD implanted just under my collarbone. I felt sore and tired but relieved to have my own ‘on-board paramedic’.

The ICD doesn’t cure the symptoms, but I know it will kick in should my life be in danger. Six months on, the device has had a minimal impact — and it hasn’t gone off, either by accident or to correct a life-threatening rhythm.

I can still do moderate exercise, but no intense training. And instead of feeling like my body has let me down, I now see my ICD as a lifeline. Thousands aren’t so lucky.