A sick toddler died in hospital after an important heart test was not done because it was the weekend, an inquest has heard.
Dylan Brown died in Hillingdon Hospital in Uxbridge on May 13 last year after suffering three cardiac arrests.
The two-year-old, who had an underlying cardiomyopathy, disease of the heart muscle, could have had an echocardiogram which uses sound waves to create a picture of the heart.
Dr Nagi Barakat, a consultant paediatrician at Hillingdon, told the inquest at West London Coroner's Court: "It was not done because it was the weekend and they are not normally done at the weekend."
The hospital has apologised to the parents, saying they were not given enough information about discussions involving Dylan.
The coroner Lorna Tagliavini recorded a verdict of death from natural causes.
She said there were no failings in Dylan's care and he was treated "appropriately".