The 41-year-old star, who has played Bianca Butcher for more than 20 years, announced her decision to leave the BBC soap this week, amid reports she is heading to Hollywood with her family.
"Patsy is really sad to be leaving the show as she loves playing Bianca and working with executive producer Dominic Treadwell-Collins but she knows it's the right decision at this time in her life," a spokesman for the mum-of-four said.
A friend told the Mirror that the actress will be heading to LA this summer to take up a "once in a lifetime opportunity".
"Not only is Patsy excited about future work in Hollywood, she is making the move for the sake of the whole family. It's a lifestyle choice for them," the insider confirmed.
"She has lots of exciting offers lined up and feels the time is right to say goodbye. Her children are at the age where they can be moved across to the States relatively easily. And it has always been her big ambition to crack Hollywood."
Patsy, whose real name is Julie Ann Harris, became an overnight hit with fans when she first appeared in EastEnders in 1993 as loudmouth Bianca.
Her on-off romance with boyfriend Ricky Butcher proved particularly popular, and the couple's wedding in 1997 pulled in one of the biggest ever soap audiences — over 22 million.
Patsy originally exited the show in 1999 before returning for a one-off episode in 2002. She reprised the part of Bianca full-time again in 2008.
EastEnders executive producer Dominic has confirmed he won't be killing off the character.
"We are so sad that Patsy has decided to leave us but completely understand the time is right for her.
"Bianca won't be leaving Albert Square until the autumn, so there's still a lot more to come from her on screen this year — and the door will be left wide open for her return. We won't be getting rid of Bianca's puffa jacket just yet."