When Sandra Oh revealed that she was leaving the hit ABC drama “Grey’s Anatomy,” we knew it was only a matter of time before fans started concocting wild theories on how her character, Cristina Yang, would depart the long-running series. Would it be in a fiery bus crash like George O’Malley, or would the sassy doctor slip away at the stroke of midnight like Denny? Whatever fate Shonda Rhimas decided for the beloved character, we knew it was going to be painful for the audience to endure.

Instead, it looks like the mastermind behind “Grey’s” opted to stick a scalpel straight through our hearts four episodes early by forcing us to watch Cristina make the most difficult decision of her life. And when we say “difficult,” we mean it. We’re talking about a decision comparable to “Sophie’s Choice.”

In episode 21, “Change of Heart,” Cristina will be forced to decide which of two children of the same family will be given a long-awaited heart transplant. Yup, grab some tissues now, because we’re about to break down the heart-wrenching sneak peek.

“Dr. Robins is on her way with a new heart for Frankie. But Ivy’s deterioration has caused her to shoot up to the top of the transplant list, too. Ivy is also a perfect match for the donor heart,” Cristina explains to the shaken-up parents.

“But that’s Frankie’s heart,” the mother replies, confused.

“Officially, yes. But under the circumstances the heart could be redirected,” the doctor replies.

“To Ivy. You want to give Frankie’s heart to Ivy?” the mother asks.

“No, I don’t want---,” Cristina stops herself and takes a breath. “Medically speaking Frankie’s condition is declining rapidly. Technically, Ivy is more stable, which would give the heart a better chance of survival.”

“But Frankie’s worse,” the mother says, now completely in tears. “Don’t you have to give the heart to the one’s that the worst?”

“Unless she thinks it’s a waste,” the father chimes in. “You think the heart will be wasted on Frankie?”

“I just want to explain all your options,” she quickly responds.

That’s when the parents completely lose it.

“Our options? This is our decision?” the father questions.

“You’re asking us to choose? You want us try picking which one of our children gets a heart and which doesn’t?” the mother asks.

That’s when the father places the responsibility on Cristina, telling her that she’s the one who needs to make the decision.

Yikes. Looks like Cristina’s last week at Grey Sloan Memorial Hospital will be one she’ll always remember. Do you think Cristina will make her decision from a medical position or will she follow her own beating heart? Chime in with your prediction in the comments section below and check back to see if you were right when “Grey’s Anatomy” airs episode 21 on Thursday at 9 p.m. EDT.