User blog comment:IamJakuhoRaikoben/Chapter 493: The White Dragneel, Review./@comment-70.179.149.246-20160711160330

I think August needs an anatomy lesson. He didn't exactly pierce her heart. While it is a common mistake that people think that the heart is located on the left side of the chest, it actually is not. The majority of the heart is located behind the sternum, just behind the esophageal tract with part of it just going laterally to the left. When Mira lifted her breast and showed her wound, August most likely just hit her in her intercostal spaces, likely broke some of her ribs (which heals on its own) or hit her lungs at the most. I know, I know, Mashima probably doesn't care for anatomical accuracy, but people seemed to be to technical on Mirajane's "heart" wounds.