The unit at Glenfield Hospital was threatened with closure in 2012 with the nearest service in Birmingham.
A series of changes have now been proposed by NHS England following a national review into children's heart services across the country.
University Hospitals of Leicester NHS Trust said the changes would see the unit move to Leicester Royal Infirmary.
On Thursday, NHS England unanimously agreed the proposals and indicated it expected the new system to be up and running in hospitals by April 2016.
Presenting the review, Ian Dodge at NHS England, said it had been "conclusive, open and transparent and rigorous".
He said: "Our analysis shows these proposals are affordable and deliverable, bearing in mind existing workforce constraints.
"These are national standards and we expect national standards to continue to apply."
Rob Sissons, health correspondent, BBC East Midlands Today
At one time this unit was going to shut and it would have been the end of services in Leicester.
Now there is talk of it surviving but it will need collaboration between Glenfield and other units up and down the country.
The recommendations passed this morning mean they will have to go from two surgeons to four and they will have to build up their case load.
It won't be a walk in the park but the hospital says they think the service can survive.
Kate Shields from University Hospitals of Leicester NHS Trust said the review would push them to provide excellent services for children and their families.
"We have worked for a really long time to show that we can sustain heart services in Leicester and we are now at the point where we feel that we have been listened to," she said.
She added the trust was already working on the proposals submitted by NHS England.
The hospital wants to move all children's heart unit onto one site at the LRI in the next three years and increase the number of procedures it carries out within the next five years.

Profits in the first three months of the year were $2.4bn. But the media giant's revenue gains more muted, up 3% year-on-year to at $13.3bn (Â£10.3bn).
The firm remains on track for modest growth, in spite of subscriber losses at its sports television network ESPN.
"We're extremely pleased with our results," said Disney boss Robert Iger.
Disney's business ranges widely, including movie studios such as Marvel and Pixar, theme parks, merchandise - even a cruise line.
Its television networks, which include ABC, Disney and the sports-focused ESPN, are the biggest earners, together accounting for more than 40% of the firm's total revenue in the last financial year.
However, ESPN has struggled with millions of subscriber losses and advertising declines in recent years, as live sports services have begun to feel the pressure from online television and viewer demands for cheaper cable packages.
This spring, ESPN laid off more than 100 people, including writers and on-air personalities.
Mr Iger said the company is confident of the demand for ESPN and pleased with the traction it is gaining on platforms such as television streaming service Hulu.
Revenue in the media unit increased 3% year-on year.
Mr Iger said the firm is focused on its mobile audience, aiming for an increasingly customised experience that allows fans to focus on news about their favourite teams.
The company plans to sell ESPN-branded streaming directly to viewers by the end of the calendar year, and that kind of personalisation is also likely to be part of the package, he added.
"Consumers will be able to buy the sports they want, when they want," he said.
Mr Iger asked analysts for "a little bit of credit" for being candid with its thinking as it grapples with the changes.
"We wanted to signal that we had our eyes wide open about what was going on," he said.
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Revenue at Disney's studio operations declined 1% year-on-year, as strong audiences at Beauty and the Beast couldn't match the firm's success last year with films such as Zootopia and Star Wars: The Force Awakens.
Strong visitor numbers at Disney theme parks and its new Shanghai resort in China helped lift the results, Mr Iger said.  The park is on track to welcome its 10 millionth guest as it nears its first anniversary, he said.
"Attendance is outpacing our most optimistic projections," he said.
Children's heart services in Leicester have been secured after a new vision was approved by a national board.
[NEXT_CONCEPT]
Profits at Walt Disney jumped 11% in the first three months of 2017, bolstered by attendance at its theme parks and resorts.