A 15-year-old girl died after deteriorating "astonishingly" quickly from a rare heart inflammation linked to Covid, an inquest has heard.
Jorja Halliday, from Portsmouth, Hampshire, died at Queen Alexandra Hospital in September last year.
She was referred as an emergency by her GP after her heart began beating fast and she struggled to keep food down.
Her mother Tracey previously said Jorja died on the day that she was due to have her Covid-19 vaccine.
She told Portsmouth Coroner's Court her daughter first started to feel unwell in the early hours of 24 September and tested positive that day.
Jorja had been prescribed antibiotics for a sore throat, but by 28 September her condition worsened and she kept vomiting.
After a GP found she had a heart rate of 147 beats per minute, she was referred to hospital.
The teenager, who was the eldest of five siblings, was placed in a medically-induced coma so she could be transferred to Southampton for specialist care.
But Jorjas condition worsened further and she died about five hours after arriving at hospital.
Dr Nicholas Tarmey treated Jorja and said: "She looked frightened, not just of the situation, she also had a sense something was seriously wrong with her body.
"Her body was struggling to cope and she was deteriorating very quickly and she looked confused and agitated."
Jorja had an inflammation of the heart called myocarditis, which Dr Tarmey said was "extremely rare" as a result of Covid-19 in children.
Consultant paediatric pathologist Samantha Holden gave a cause of death of acute myocarditis associated with Covid-19 infection and added: "She was the only child I have seen that has Covid myocarditis."
When asked by Ms Halliday if Jorja would have suffered a less severe reaction if she had received a Covid-19 vaccination, Dr Tarmey added: "It's such an unusual situation.
"I suppose having a Covid jab might reduce the risk of these complications but I am extrapolating that from the benefits we know."
Giving a verdict of natural causes, coroner Sarah Whitby said Jorja's condition had deteriorated "astonishingly" quickly.
After the inquest, Ms Halliday encouraged people to consider getting a Covid-19 vaccination and said: "Covid can do this to fit and healthy young people, however rare it is, it can happen."
Ms Halliday previously said Jorja, a GCSE student at The Portsmouth Academy, was a "loving girl", talented kickboxer and an aspiring musician.
She added: "It's heart-wrenching because your kids are always meant to outlive you, and that's the one thing I can't get over."
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