Since the green ray is the core of the positive polarity, I would submit that it's better to view "overactivation of the heart" as "the underactivation of other chakras". A subtle but significant difference in perspective.
In other words, don't close your heart if you believe it is overactivated - please continue to do and feel green ray stuff - but focus on working on empowering and undistorting the under-activated other rays.
In other words, don't close your heart if you believe it is overactivated - please continue to do and feel green ray stuff - but focus on working on empowering and undistorting the under-activated other rays.