While he wasn't actually performing CPR or banging on Adam McKay's chest, Christian Bale indirectly helped to save the director's life - and it was all thanks to the actor's diligent research.

In an interview with Deadline, McKay explained that during the production of 'Vice', the upcoming biopic on Dick Cheney, he'd put on a little weight and was smoking more than usual. "My doctor had told me, you got to stop doing this, and I kept saying, please don’t let me have a heart attack while I’m doing a movie about Dick Cheney," said McKay, citing the fact that Cheney himself had suffered five heart attacks from 1978 up to 2010.

As McKay explained it, when the movie wrapped, he called his trainer and began working out to start losing weight. "Our third workout, I get tingly hands and my stomach starts going queasy. I always thought when you get a heart attack, it’s pain in the chest or the arm. But then I remembered. When we shot one of the heart attack scenes, Christian Bale asked me, ‘how do you want me to do it,’ and I go, ‘what do you mean? It’s a heart attack. Your arm hurts, right?’ He says, ‘no, no. One of the more common ways is that you get really queasy and your stomach hurts.’ I said, ‘Really?' I’d never heard that before."

Thankfully, McKay remembered the symptoms and quickly downed a bunch of aspirin, called his wife who called 911, and made it to the hospital on time. McKay's since had a stent put in his heart to repair the damage.

What's more, a week later, he told Bale all about it. "I called Christian a week later and said, either you or Dick Cheney just saved my life," McKay said. "After asking again and again for 10 minutes if I was really alright, we just started laughing."

'Vice' hits Irish cinemas on January 25th.