A 70-year-old man uttered "this is the most excruciating pain I've ever had" as his two daughters administered CPR "desperately trying to save his life" almost 70 minutes after calling an ambulance.
The man, from south-east London, died of a suspected heart attack moments later, on November 1st, the BBC reported.
One of his daughters arrived at his home before the ambulance did, and delivered CPR after her father stopped breathing.
The London Ambulance Service is now investigating its response to the incident.
The man's other daughter, neither of whom wish to be identified, said: "The emotional trauma of witnessing this and desperately trying to save his life, knowing he was seriously let down, is overwhelming.
"His last words to (Emma) was that 'this is the most excruciating pain I've ever had' and she now has to live with that.
"Nothing will bring him back but we will do all we can to make sure no-one else loses their life unnecessarily and no-one else goes through this trauma."
The panicked daughters made several emergency calls.
They said they were initially told an ambulance would be with them "within 41 minutes from the first call".
Their father stopped breathing an hour after 999 was first called, at which point another emergency call was made while one daughter gave him CPR.
The incident was redefined as Category 1, reserved for the most serious incidents, and then arrived shortly afterwards, 69 minutes after the first call.
Ambulances in England aim to respond to Category 2 calls, such as major burns, epilepsy and strokes, in an average time of 18 minutes.
Category 1 ambulance calls are those that are classified as life-threatening and needing immediate intervention and/or resuscitation, e.g. cardiac or respiratory arrest. The aim is to respond to these within seven minutes, according to Nuffield Trust.
However, under-pressure NHS England services recorded average response times of 54 minutes last month, compared to a target of 18 minutes, The Mirror reported.
An LAS spokesperson said: "Our thoughts are with the patient's family and friends during this difficult time and we send them our deepest condolences.
"We are looking into how we responded to the patient, and would encourage the family to reach out to our patient experiences team so we can support them in reviewing what happened."
Source: Read Full Article