Hollywood star Arnold Schwarzenegger has shared a scary but inspiring story about having open heart surgery, saying life is all about overcoming obstacles.

He recalled his emergency heart operation while delivering speech to students graduating in 2020. The "Terminator" star later posted the speech on his Instagram, reports metro.co.uk.

In the clip, he recounted his health scare, which occurred just before he started shooting "Terminator 6: Dark Fate" two years ago.

"Congratulations to the class of 2020. I'm not going to stand here and bullsh*t you about this being a fantastic time to graduate," began the 72-year-old.

"I can promise you this coronavirus won't be the last obstacle that you face. But it can help you prepare for the next one. That's what life is all about, overcoming obstacles," he said.

After discussing the coronavirus pandemic, the movie icon shared his own story.

He said: "I got a physical. I went to the doctor and he checked me up, that's what you always do before you start a movie. The doctor said 'You're in great health, but I'd recommend that you go and replace your heart valve. It's leaking blood'."

The actor continued: "So I said, 'I'm not going to have open heart surgery now, four months before shooting. Are you crazy?' I was just in the middle of working out with heavy weights, getting ready, doing my stunt training and everything. He says, aNo, no, the technology has changed. This is not open-heart surgery anymore. This is a non-invasive surgery that goes through your artery in the bottom up to your heart, replace the valve, and the next day you go home. A week later, you can continue with your regular training'."

"Then I remembered that a friend of mine, a 90-year-old producer, had the procedure done just recently. Two days after, he was at a meeting at a studio in Hollywood and he looked fantastic. So I said, 'Okay, I'll do it'. So after I woke up from the surgery,A I woke up 16 hours later instead of four hours (later). And there was a tube sticking out of my mouth. The doctor moved forward, took the tube and ripped it out of my throat. And I was coughing violently, and he says, "Just keep coughing. And then let us tell you what happened."

The actor said that the doctors told him that "they had to do emergency surgery".

"That something went wrong during this non-invasive procedure. And then it became very invasive. They said they broke through the heart wall and there was internal bleeding and I could have died if they didn't open up my sternum and do open-heart surgery. 'Imagine, the day before I was training really hard, and now all of a sudden he's telling me they were saving my life. Then he says 'You're not out of the woods yet. There's another danger. There are still patients in our heart unit here, who after heart surgery, pass away, not because of the surgery but because of the lung. They get pneumonia. So we're really worried about you getting pneumonia'."

The actor then explained that he had to do the breathing exercises while practicing walking with a walker.

He called the experience "unbelievable", saying: " but added: "My usual principles worked."