Prince Philip could be in hospital for another six weeks, according to an expert.
The Duke of Edinburgh has already been in hospital for two weeks after walking in under his own steam on Febraury 16.
He was being treated for an infection at King Edward VII hospital in Central London, then yesterday he was moved to the specialist cardiac unit at St Bartholomew’s.
NHS cardiologist Dr Aseem Malhotra told The Mirror: “It’s more likely he had an infection elsewhere.
“It could’ve been in the urinary tract or a chest infection and the stress on his body put strain on his heart.
“Therefore he had to be taken to a specialist cardiac centre to make sure heart is functioning while he is treated for the infection. What makes it more likely is his underlying heart issues.
“This is all speculation and it’s difficult to draw conclusions with the limited information.
Police officers clear a pathway for the ambulance carrying the Prince as it leaves the rear of the King Edward VII Hospital (Image: PA)
“He’s far healthier than the average person of his age and is clearly a very robust and resilient man.
“I wish him very well and hope he gets better soon.”
Buckingham Palace said: “The Duke remains comfortable and is responding to treatment but is expected to remain in hospital until at least the end of the week.”
Buckingham Palace had previously said the Queen’s consort was staying in hospital for “rest and recuperation” and only admitted “with an abundance of precaution”.
A week later aides revealed the royal – who turns 100 in June – was being treated for an infection but “responding well to treatment”.
Philip has been visited by Prince Charles, 72, on the first weekend he was in hospital and could be visited by other members of the family in the coming days.
Last Tuesday, when it was announced the duke would spend several more days in hospital being treated for the infection, the Earl of Wessex said he had talked to his father on the phone and he was “a lot better”.