It happened a day after grandfather Wayne Irving, 67, died following a three hour wait in an ambulance outside an Ipswich hospital, west of Brisbane.
QAS has launched a review after Cath Groom waited 90 minutes at her Forest Lake home in Brisbane's south for paramedics to arrive.
Ms Groom called Triple-0 about 10.30pm on Friday, complaining of chest pains.
QAS said the incident was prioritised as requiring a "lights and sirens response" but there was a high level of demand at the time.
Her family called at 11pm to check if an ambulance was coming and 20 minutes later a QAS clinician rang back for an update on Ms Groom.
But paramedics still failed to arrive and her family eventually cancelled the ambulance by midnight.
Her family said Ms Groom went to bed hoping to seek treatment in the morning but she never woke up.
Her family discovered her body the next day, which marked her 52nd birthday.
"We obviously should have done better in this set of circumstances," QAS Commissioner Craig Emery told reporters on Tuesday.
"We should have responded to that patient in a much more timely manner - 10 to 15 minutes would be an appropriate response time."
Health Minister Shannon Fentiman has announced Ipswich hospital upgrades to improve patient flow.
Health Minister Shannon Fentiman said the incident was "unacceptable".
"It is not good enough," she told Nine Network's A Current Affair program on Tuesday night.
A full clinical review has been launched into the death of not only Ms Groom but also Mr Irving.
He is believed to have suffered a fatal heart attack as he was being transferred from a stretcher to an Ipswich hospital bed after waiting three hours outside in the back of an ambulance.
Ms Fentiman has announced Ipswich hospital upgrades to help improve patient flow following Mr Irving's death.
She said there would be 12 extra beds at the emergency department's short stay unit and 24 new beds in acute wards.
"We know our emergency departments are seeing more people than ever before," she said.
"Despite those huge numbers we are seeing ED wait times come down.
"The median wait time is now 15 minutes across the state.
"Ipswich has had better performance in the last three months but I acknowledge there is a long way to go."
A GoFundMe fundraiser has been set up for foster carer Mr Irving's family, including his wife of 43 years Barbara.
"Wayne had a soul that beamed happiness and pride all the time," the fundraiser page said.
"You could see it in his eyes when he was surrounded by his family.
"Unfortunately Wayne's death was unexpected and no life insurance was in place, leaving Barb and his foster family in a hard financial state."
Opposition health spokesperson Ros Bates said ambulance ramping outside hospitals had to be addressed.
"The Palaszczuk Labor government have missed their ramping targets for the last seven years and this has mortal consequences," she told reporters.