It wasn't exactly a heart-attack, Marcos. Her heart actually stopped beating for a period of time (I think about 7 minutes), and it was caused by a chemical imbalance. We've been told that she did have an eating disorder (exactly what it was, I haven't heard) but doctors believe that the eating disorder is what caused the chemical imbalance. Because her heart was stopped for so long, her brain was massivly affected, killing off most of her brain cells. She was also taking medication because of it, I think in an effort to come out of the eating disorder.
Her husband, Michael, sued the drug company that manufactured the medication and won the lawsuit. I haven't heard exactly how much they got for it, but it was to be used specifically for her care. That's how she ended up in the Hospice with the feeding tubes and all that. The only things that indicated she was even still "alive" was that she could blink, could kind of make "nnnnnggghghhh" type sounds, and her heart was beating.
That's just kind of a brief (very brief) overview of the story. All major news sites are coving the story, like Newsweek, CNN, Fox News, New York Times, Wall Street Journal, NBC/MSNBC, etc. You can visit one of their sites if you'd like more information.
H-D