My older sister used to say the same thing to me about swallowing chewing gum "it will wind around your heart and you will die!" It put me off having chewing gum for several years. Looking back, I think it was probably because she didn't want me to take any of her chewing gum! Even when I was a few years older, I always used to be careful when having chewing gum or bubble gum, to make sure I didn't swallow any of it by accident!