Dr. Cristina Yang's time at the Grey Sloan Memorial hospital will soon come to an end, but she still has some very important decisions to make.

Dr. Cristina Yang's Goodbye Details with Owen and Preston 

In a teaser from Thursday's episode of Grey's Anatomy, titled "Change of Heart," Cristina (Sandra Oh) is seen telling two emotional parents some bad news.

"Dr. Robbins is on her way with a new heart for Frankie, but Ivy's deterioration has caused her to shoot up to the transplant list too. Ivy is also a perfect match for the donor heart on route," Cristina tells them. "Medically speaking, Frankie's condition is declining rapidly. Technically, Ivy is more stable, which would give the heart a better chance of survival."

First Photos of Isaiah Washington As Burke On Set  

The children's mother is in tears as she asks, "Don't you have to give the heart to the one that's the worst?"

"I just want to explain all your options," Cristina responds.

"We can't choose," the father responds. "You have to do it."

Many fans were shocked when Oh announced in August that she'd be leaving the ABC show. The 42-year-old actress, who appeared on the show since season 1 premiered in 2005, said she wants to start a new chapter in her life.

"Creatively, I really feel like I gave it my all, and I feel ready to let her go," Oh told The Hollywood Reporter. "It's such an interesting thing to play a character for so long and to actually get the sense that she wants to be let go as well."

Isaiah Washington is set to reprise his role as Dr. Preston Burke for one episode in May and his appearance will play a significant role in the departure of Oh's character.

"It's important to me that Cristina's journey unfolds exactly as it should," said show creator Shonda Rhimes in a statement. "Burke is vital to that journey - he gives her story that full-circle moment we need to properly say goodbye to our beloved Cristina Yang."

-- Grey's Anatomy airs Thursdays at 9 p.m. ET on ABC.

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