NEW YORK — Arnold Schwarzenegger is recovering in a Los Angeles hospital after undergoing heart surgery.

The 70-year-old former California governor had a scheduled procedure to replace a pulmonic valve on Thursday, according to Schwarzenegger’s spokesman, Daniel Ketchell. He was in stable condition on Friday.

“His first words were actually ‘I’m back,” so he is in good spirits,” Ketchell tweeted.

The operation was necessary to replace a valve that had originally been installed in 1997 for a congenital heart defect. “That 1997 replacement valve was never meant to be permanent, and has outlived its life expectancy,” Ketchell said. Schwarzenegger opted for a less-invasive catheter valve replacement procedure.

An open-heart surgery team was ready during the procedure, but Ketchell said their presence wasn’t unusual in such circumstances.

Schwarzenegger was a bodybuilding star before turning to movies. His career as an action hero took off with the box-office hit “Conan the Barbarian” in 1982. His role in the “Terminator” in 1984 propelled him into box-office superstardom. He served as governor of California from 2003 to 2011.

In addition to his heart ailments, Schwarzenegger had a motorcycle crash in 2001 that left him with several broken ribs. He’s had a hip replaced and had rotator cuff surgery in 2003.