A woman who died after collapsing in a court building was in "a potentially survivable situation", a coroner said.
Hayley Gascoigne, 32, from Scunthorpe, fell ill in the public concourse area of Hull Combined Court Centre in January and was later pronounced dead.
A pre-inquest review heard a report had stated the first paramedic on the scene did not "effectively manage the shock-able cardiac arrest".
Hull Coroner Prof Paul Marks said she died from hypertensive heart disease.
He said a report by the Yorkshire Ambulance Service found the mother-of-four "probably" had a shock-able heart rhythm, but this was not addressed by the rapid response vehicle (RRV) paramedic.
"A variety of conclusions have been found [in the report]," he said.
"The root cause of this incident has been established as the RRV paramedic did not effectively manage the shock-able cardiac arrest.
"I'm slightly concerned that this is a natural cause of death which, in a sense, was unnatural. There was a natural cause of death but it came unnaturally because of lack of action.
"I'm minded that this was a potentially survivable situation."
Prof Marks added: "Hayley was young. We need an expert view to determine if the shock-able rhythm was treated she would have survived."
Prof Marks said he was concerned the stress of the court hearing Miss Gascoigne was involved in could have led to her "tragic death".
Miss Gascoigne went into a cardiac arrest after the conclusion of a hearing involving her children.
A three-day inquest is due to take place at a later date.
Following her death, friends of Miss Gascoigne described her as "a lovely, warm kind person".