By Anthea Beattie, 49, from Wigton, Cumbria explains how her once-sporty girl came to a standstill.

TAGS:

Answering my mobile, I wasn’t expecting to hear my daughter Zara’s voice. It was an afternoon last May and Zara, then aged 12, was at school.

‘I don’t feel good,’ she told me.

She said she’d had a funny spell during PE and thought she was going to pass out.

Zara has asthma and had used her inhaler in the lesson. Her chest still felt tight, though, and she’d had heart palpitations.

‘It sounds like an asthma attack,’ I told her.

Despite her condition, Zara played a lot of sport.

I assumed she’d over-exerted herself, but took her to the doctor, who checked her heartbeat.

It was 120 beats per minute (bpm).

‘That’s high,’ the doctor said. ‘Around 70 is normal.’

Zara had an ECG, but the results were normal.

A few weeks later, I had to take her to Cumberland Infirmary to have more tests.

There, her heart rate was monitored for four hours.

During that time, she went to use the loo and her heart soared to 130bpm.

Zara was referred for an echocardiogram and the specialist was baffled to find that her heart looked healthy.

SWNS

My husband Ian, 54, read about a condition online called postural tachycardia syndrome (PoTS).

It’s an abnormal increase in heart rate, that occurs after sitting up or standing.

‘Could Zara have PoTS?’ Ian asked doctors.

They said it was likely, but that there was no single test to confirm it.

PoTS is more common in women between 15 and 50 – but Zara was 12, so her case was extremely rare.

The condition causes heart palpitations, dizziness, fainting, fatigue and shortness of breath…

‘When you sit up, gravity pulls some blood down to your belly, hands and feet,’ a doctor explained.

In response, blood vessels quickly narrow and the heart rate increases to maintain blood flow to the heart and brain.

‘This is all done by the autonomic nervous system,’ the doctor continued.

But in PoTS, the autonomic nervous system doesn’t work properly, so blood isn’t pushed back up.

There’s no known cure, although there were unlicensed trial drugs she could try, including anxiety meds.

But they made her feel worse.

Back at home, Zara struggled. Walking up the stairs left her breathless and feeling faint. Even standing for more than a few minutes sent her heart rocketing.

Some days, Zara would so tired, she’d be in bed all day and soon she had to be home tutored.

SWNS

She kept in touch with her friends on social media and they came over to visit her as often as they could.

Zara’s 13 now, and spends most days lying on the sofa to keep her heart rate steady. Standing and moving about just makes her feel faint.

She only leaves the house to go to hospital and then she’s in a wheelchair.

Doctors can’t be sure what causes PoTS.

We don’t know if Zara will get better or worse.

She recently saw a specialist, Professor Norton, at the Falls and Syncope Clinic in Newcastle’s Royal Victoria Infirmary.

Since then, we’ve been feeling really positive.

Zara’s life has been flipped upside down. But she amazes me with her incredible spirit.

Despite it all, she’s the one picking me and her dad up with her jokes and smiles. Ian and I are so proud.