I can't really follow either one; they're both organs.
But if the question is meant to be taken figuratively, I guess a different answer is in order.

I don't follow my heart for the simple reason that my "heart" and my "head" are one in the same. The notion that the heart and mind are two distinctly different emotion-governing entities is foolish at best. With any situation you come across, you think it through and take the appropriate course of action based upon your assessment. Whether said action has more to do with empathy or reason depends entirely upon the kind of person you are.

And in many cases, either choice would have been right.