Why does Mrs. Mallard really die in Kate Chopin's "The Story of an Hour"?
At the end of Kate Chopin's short story, "The Story of an Hour," the doctors say that Mrs. Mallard died from a heart attack caused by the "joy" of seeing her husband alive. She was known to have "heart trouble." He had been presumed killed in a "railroad disaster." Upon hearing the news of his death, she immediately grieves for him, but she eventually comes to a very important realization after spending time alone. Instead of being depressed, she knows that for the first time in her life she is free.
In the 19th century, when the story was written, women were very much second class citizens ruled by their husbands. Much of Chopin's writing is about women trying to break away from this "repression." The awareness that she can now control her life brings overwhelming happiness. Chopin writes,
There would be no one to live for her during those coming years; she would live for herself. There would be no powerful will bending hers in that blind perspective with which men and women believe they have a right to impose a private will upon a fellow creature.
Now able to exact her own "will" she whispers to herself, "Free! Body and soul free!" She looks forward to making her own decisions, and a life she once thought "might be long" is spread out before and she "breathed a quick prayer that life might be long."
Thus, the shock that makes her heart stop isn't joy from seeing her husband alive, it is shock at losing her new found freedom which she was very much looking forward to experiencing.