At 28, Matt Ullmer couldn’t have seemed fitter or healthier. A competitive amateur cyclist, he would regularly cover distances of more than 100km in a single session.

He didn’t smoke, drank in moderation and, to the naked eye, appeared to be in great shape.

So, when, in 2015, he began to experience dizzy spells, the supermarket logistics worker from Cheltenham at first brushed them off as a symptom of over-exercising.

‘Initially, it would only happen when I was running, not cycling,’ says Matt, now 37. ‘Out of nowhere, I start feeling unsteady and would have to stop and brace myself against a wall or a tree.

‘But it would eventually pass and I could finish my training session.’

Eventually, when the spells didn’t go away, Matt made an appointment with his GP.

However, the family doctor told Matt that he had nothing to worry about.

‘He just looked me up and down, and said I was a fit and healthy man who just needed to take it easier,’ he says. ‘He didn’t suggest any tests or scans.’

However, overtime, the dizzy spells became more frequent and severe. Matt also noticed that he was feeling increasingly fatigued.

‘My performance on the bike dipped,’ he says. ‘I’d won races in previous years, but over about six to nine months I could feel myself getting weaker.’

Then, in July 2016, while out on a training ride with his friends in the Cotswolds, Matt collapsed.

His friends called an ambulance, and Matt was rushed to John Radcliffe Hospital in Oxford. Doctors quickly realised Matt had suffered a cardiac arrest – a life-threatening condition where the heart suddenly stops beating.

Matt was rushed into intensive care where he was put into an induced coma and given a range of medication to stabilise his heart.

When Matt awoke three days later, a cardiologist told him that they had found the cause of the cardiac arrest: his heart was severely inflamed, possibly due to a recent infection.

The condition, known as myocarditis, enlarges and weakens the heart, forcing it to work harder to circulate blood and oxygen throughout the body. Overtime, it can scar the heart and disrupt its pumping with deadly consequences.

It is often triggered by a bacterial or viral infection, like the flu. It can affect people with no history of illness and studies suggest it is particularly common in men aged between 20 and 30.

Common symptoms include chest pain or discomfort, shortness of breath, unusual tiredness, heart palpitations, and dizziness. Caught early, myocarditis can be easily treated with medicine and rest.

However, in many cases, like Matt’s, GPs and A&E doctors miss the signs of the deadly condition.

While in hospital, Matt was fitted with a surgically implanted defibrillator, designed to monitor his heart rhythm and deliver electric shocks if it sensed any problems.

He was also given specialist heart rhythm tablets and blood-thinners, in the hope that these would help the inflammation in his heart go down, and the organ’s function  improve.

However, once discharged, Matt’s health did not get better. In fact, he has struggled with increasingly severe symptoms for much of the past decade.

As he attended regular hospital checkups, Matt was told his heart function had fallen from around 60 per cent to, last year, just 16 per cent.

This was due to the severity of the scarring to his heart, which, it turns out, had led to permanent damage.

Matt attempted to keep exercising, regularly cycling and walking. However, as his heart continued to fail, he found that simple tasks like walking short distances became impossible.

Earlier this year, he was forced to quit his job and decided to move in with his parents so they could look after him as he felt he wasn’t well enough to live independently.

Then in May, he suffered another cardiac arrest while at home – just weeks before he was due to attend a hospital appointment to discuss going on the transplant list.

Kept alive by his father who performed CPR until an ambulance arrived, Matt was taken to the Queen Elizabeth Hospital in Birmingham. Doctors were able to stabilise Matt, but his family were told he would need an urgent heart transplant to keep him alive.

Thankfully, Matt only had to wait two weeks before a suitable donor organ was found, and at the end of June he received his new heart.

Matt says he counts himself lucky because he was able to get a transplant so quickly.

However, he believes his two near-death experiences, combined with the decade of debilitating poor health, could have been avoided, if his GP had caught the myocarditis early.

He’s now urging patients who experience similar symptoms to push their family doctors to test for myocarditis.

‘If I or my GP had known about myocarditis earlier, when my symptoms first showed, I could have gone for scans and had medication and made other changes which would’ve given me a much better prognosis,’ he says.

‘The irony is that it was my fitness which masked those symptoms – but by the time of my first cardiac arrest, so much irreparable damage had already been done.’

Not all cases of myocarditis are life-threatening – or severe enough to cause lasting damage.

Research shows that around 2,000 people in the UK are admitted to hospital every year with myocarditis, while around 250 die as a result.

Experts say that many people will develop myocarditis without realising it.

According to Dr Sanjay Prasad, a heart expert at the Royal Brompton Hospital in London, roughly one in every 100 people will develop myocarditis in their lifetime.

‘There are so many undiagnosed cases because the problem often resolves itself without treatment,’ says Dr Prasad. ‘It’s rare that it’s fatal, but we believe that undiagnosed myocarditis kills around one young person in the UK, on average, every week.’

The problem often occurs when infections, such as the flu, directly infect the heart muscles. It can also happen when the body’s immune reaction to the infection accidentally damages the organ too.

Experts say that this means many patients believe their symptoms are after-effects of the infection – rather than any issues with their heart.

In recent years, there has been a marked increase in myocarditis cases in the UK, according to research.

This is, in part, due to the arrival of the Covid virus, which led to an uptick in myocarditis hospitalisations in the UK. However, research has also shown that some of the most commonly used Covid vaccines, in rare cases, left patients with myocarditis.

Studies show that young men were most likely to develop the heart problem after taking the Pfizer and Moderna jabs – for reasons that are still unclear.

Experts say, caught early, myocarditis patients can be monitored and given medication if necessary. This includes anti-inflammatory tablets, to ease the swelling, and antibiotics, if the problem is due to an ongoing bacterial infection. 

The condition is usually diagnosed by scanning the heart in hospital. But experts say that many GPs fail to refer patients for these tests because they miss the signs of the condition. 

'Many GPs fail to diagnose myocarditis because it often affects otherwise young, healthy individuals, so they assume cardiac issues are unlikely,' says Dr Prasad.

'Added to that is that myocarditis is relatively rare, there are limited testing facilities in GP surgeries for myocarditis, and symptoms often mimic other illnesses like flu or chest pains.

‘If you’re young with chest pain, breathless, dizziness, palpitations or fatigue that persists for more than two weeks after a viral infection, the message for patients is to get seen and ask your doctor whether myocarditis should be considered.’

Matt Ullmer says he can’t remember having the flu in the lead-up to his dizzy spells. 

‘However, I was very prone to chest infections in my 20s,’ he says. ‘So it’s possible that the inflammation began years earlier, before I had any symptoms.’

Matt is now back to walking short distances to rebuild his strength and tests show he has normal heart function.

Matt’s girlfriend, Mollie Heyworth, is planning to run next year’s London Marathon in order to raise money for Myocarditis UK. The charity funds research into new treatments for the heart condition, but also to raise awareness of the little-known issue.

Matt says he had never heard of myocarditis until his illness, and wants others to learn the symptoms, such as dizziness, so they can escape the same ordeals that he has faced.

‘Both my GP and I thought because I appeared to be very fit and healthy, I'd be fine,’ he says. ‘Now I’m recovering after a heart transplant and wish I’d known more.'

To donate to Mollie Heyworth marathon fundraiser, visit: www.justgiving.com