A child who died of a "very rare" condition could have reasonably been diagnosed about four hours earlier, experts told a coronial inquest. Five-year-old Rozalia Spadafora is believed to have died from influenza-A induced myocarditis at Canberra Hospital on July 5, 2022. Three experts answered questions on various aspects of her care on Wednesday. Rozalia waited five hours in the emergency department waiting room, and a failure to check her blood pressure during a routine observation check may have delayed her treatment further. In an ideal world, Rozalia would have been diagnosed 10 to 12 hours before she was, emergency physician Dr Robert Day said. However, two other experts said that estimate was overly optimistic. Rozalia was diagnosed with myocarditis at about midday, but should have reasonably been diagnosed at around 7-8am, the experts agreed. Myocarditis is inflammation of muscle of the heart and can be caused by a virus or a post-infection immune response, paediatric infectious disease specialist Associate Professor Mike Starr told the court on Wednesday. "Many clinicians will go through their careers without seeing [it]," Dr Starr said. He said the symptoms are also common in other conditions, particularly viral illnesses. Paediatric intensive care specialist Dr Festa said an aggressive and life-threatening version of the condition is even more rare. Dr Starr said he believed this condition is what killed Rozalia. He said about about half of children with the form of myocarditis Rozalia had would die from it. If Rozalia had been taken to Sydney, she would have had to survive transportation and then would likely be put on an ECMO machine - life support for people with possibly fatal issues that impact their heart or lungs. "That doesn't guarantee survival," Dr Festa said. He said the likelihood of survival for people who need ECMO support in a children's hospital is about 50 per cent. Rozalia may have needed a heart transplant. However, the experts agreed there were numerous errors and poor communication that meant what Dr Festa called the "window of opportunity" for Rozalia to survive was lost. This included a failure to reconsider different possible diagnoses from an original assumption, properly interpret a heart scan, communicate effectively across different departments, allocate responsibilities clearly and seek advice from Sydney-based specialists. The experts outlined systemic issues within the hospital which lead to poor communication between staff. Dr Day said: "Clearly communication can be difficult in very busy emergency departments ... that's why there needs to be clear processes." Dr Day said myocarditis can occur in otherwise healthy children. In Rozalia's case, it was either caused directly by influenza A or from a post-viral immune response. Rozalia was not vaccinated against the flu. Dr Day said pre-COVID influenza rates for children were low, and even more-so since the pandemic. Dr Starr noted that while flu vaccination was important, there is no guarantee it would have protected Rozalia against getting the virus. However, all experts agreed all parents should prioritise vaccinating their children against influenza every year. Dr Festa agreed that myocarditis in children would more commonly be seen in more specialist hospitals than those in the ACT. However, he said referring hospitals such as Canberra Hospital needed to be aware of the condition. "Individual hospitals will get sporadic cases," he said. Dr Festa said knowledge gained in the big hospitals should flow down to "make sure these children are identified and properly managed". The inquest continues on Thursday.