Board Thread:General Discussion/@comment-24386552-20140620194012/@comment-4287993-20140620195400

Izzie's death medically differed from Meredith's. Izzie had (i believe it was) a cardiac arrest, which has to be treated within minutes or you permanently die. She only had a few minutes to spend in the afterlife then, or she would've been dead forever. Meredith's condition took more time, so more time in the afterlife.