An Ambulance Victoria manager says late ambulance arrivals for urgent cases are unacceptable after four heart patients died waiting for emergency help.
Four patients died within four days in the past week after suffering cardiac arrest, according to figures provided by the Victorian Labor opposition.
In each case, they experienced ambulance waits of between 18-22 minutes, outside the government's time guidelines.
Ambulance Victoria general manager of regional services Tony Walker says the cases are under review.
One involved a 63-year-old Rochester man who died after cardiac arrest on Saturday. An ambulance took 22 minutes to arrive.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"Twenty-two minutes for a cardiac arrest is not an acceptable response time, I wouldn't even try and defend that," Mr Walker told Fairfax Radio on Monday.
In another case, a 60-year-old man suffered cardiac arrest at Riddles Creek and an ambulance took 18 minutes to reach him.
Mr Walker said although Victoria has some of the best survival rates from cardiac arrest in the world, it does not help in cases where an ambulance does not arrive in time.
"If we can't get there quickly, and these two cases have highlighted that, then maybe we didn't give these people the best chance," he said.
Mr Walker says the service is tackling delays for non-threatening cases and working to reduce demand on the emergency ambulance fleet for cases that don't require it.
An expansion of a referral service announced by the government last week would help with that, he said.
"We are under pressure, I won't deny that," he said.
Labor's parliamentary secretary for health Wade Noonan said the government has to acknowledge the system is in crisis and act urgently.
"This is a mess and people are dying and Denis Napthine needs to come forward and set out a plan so Victorians can have confidence in their ambulance service," he said.
A spokesman for Health Minister David Davis said legitimate concerns about service quality are investigated by Ambulance Victoria.
"Cases where a death may have occurred due to a procedural issue or delay will be dealt with appropriately," he said.
He said the coalition government invested a record $662 million in Ambulance Victoria and recruited an extra 465 paramedics.
