Stress caused by hitting a runaway dog contributed to the death of a 64-year-old woman who suffered from severe heart disease, a coroner has found.
Office administrator Susan Margaret Smith, 64, died after the vehicle she was in hit a dog on Ohauiti Rd last year.
Smith, 64, of Hamilton, died in Tauranga Hospital emergency department on October 11 fewer than four hours after the incident.
In a written decision, Coroner Donna Llewell said the direct cause of Smith's death was the result of severe coronary artery disease, preceded by a historical ventricular myocardial infarction which happens when blood flow to a part of the heart diminishes or stops.
The stress of the event was also a significant contributing factor.
Smith, her husband Norman and her sister-in-law were involved in a crash on Ohauiti Rd in Tauranga involving a dog about 11.30am on October 11 last year.
Smith was in a wheelchair in the rear passenger area of a rental mobility van driven by her husband with her sister-in-law seated beside him.
As the trio headed along Ohauiti Rd, a dog ran on to the road causing Norman Smith to brake hard to try to avoid hitting the animal.
Witnesses first on the scene told the police the wheelchair was anchored and secured in place but was removed to help Margaret Smith after the crash.
Coroner Llewell said the sudden stop and impact with the dog resulted in Margaret Smith being thrown out of the wheelchair, hitting her head heavily on the back of the front seat.
"She may not have been wearing her lap belt provided in the van to keep herself in the wheelchair," she said.
Emergency services attended and within 15 minutes Smith lost consciousness and paramedics believed she was having a stroke, the coroner said.
Once at Tauranga Hospital, she had a CT scan that showed no signs of bleeding but there were suspicions there may have been a chronic blood clot into the cerebral vasculature.
However, before further CT imaging could be obtained, Smith's heart rate slowed and her blood pressure spiked and she died at 3.05pm.
A post-mortem revealed evidence of severe stenotic calcified coronary arteries, a large old left ventricular myocardial infarct (a heart attack), an atheroma (build-up of materials) in the distal aorta, minimal external trauma and skeletal muscle atrophy.
Pathologist Dr Tim Sutton also noted she had a history of muscular dystrophy. The only mark on her body was a small mark on her hip.
Sutton said he believed the accident probably precipitated Smith's death by causing adrenaline to increase blood flow throughout her body.
He found Smith's heart was "astounding" and described Smith as having been "living on the edge" and said if she had been mobile she would have died sooner.
A police Serious Crash Unit investigated the crash and found no defects with the vehicle and concluded speed and alcohol were not contributing factors.
Crash investigator Senior Constable Ian Shields said the dog's owner confirmed their pet died as a result of the crash.
Shield's job sheet said parked vehicles would have made the dog hard to see.
Shields said there was nothing to suggest the wheelchair was not correctly anchored to the Toyota van given the first witness accounts.
"The only concern was whether Mrs Smith was wearing the lap belt which would hold her in her wheelchair in an emergency."
Coroner Llewell said she was satisfied a coroner's inquest was not needed.