Arnold Schwarzenegger Speaks Out After Open-Heart Surgery: 'It’s True: I’m Back!'

Arnold Schwarzenegger is on the mend after undergoing open-heart surgery.

The actor, 70, took to social media for the first time on Monday since it was revealed he had an emergency operation following complications that arose during a planned heart valve replacement.

“It’s true: I’m back! I went to sleep expecting to wake up with a small incision and woke up with a big one,” he tweeted. “But guess what? I woke up, and that’s something to be thankful for.”

Schwarzenegger thanked his team of doctors and nurses, and expressed “gratitude” for his fans.

“Thank you to the doctors & nurses,” he continued. “And I’m truly filled with gratitude for all of the kind messages.”

On Friday, Schwarzenegger’s representative Daniel Ketchell said the actor was in “good spirits” following the surgery.

In a statement, Ketchell said, “Yesterday, Governor Schwarzenegger underwent a planned procedure at Cedars-Sinai to replace a pulmonic valve that was originally replaced due to a congenital heart defect in 1997.”

The replacement the actor underwent nearly 20 years ago was “never meant to be permanent,” so Schwarzenegger “chose to replace” it on Thursday “through a less-invasive catheter valve replacement,” Ketchell added.

An open-heart surgery team was standing by in case of complications, which is common during these types of procedures, according to Ketchell. When complications arose during the procedure, the doctors on standby were able to successfully step in and perform open-heart surgery, the actor’s rep confirmed to PEOPLE.

“Governor Schwarzeneggers’ pulmonic valve was successfully replaced and his is currently recovering from the surgery and is in stable condition,” Ketchell added, before thanking the “entire medical team for their tireless efforts.”