I've heard of things like this before. My boss has been on doctors orders to avoid caffeine for about 6 months as it makes his heart race dangerously. If it were me I'd take my chances, as somones sig says "death before decaff" :-D
I too have been asked to get off caffine due to heart racing. It was explained to me that my heart is fine, I'm at no risk of heart attack or anything. It's an electrical impulse issue the is heightened by caffine. It more annoying for me than anything so I stay off the caffieine. I drink tons of decaf coffee though cause I love coffee.