The pect minor pain sometimes does feel like it is going to your breast tissue as well as where the heart is. Ofcourse you have to have your heart checked out to be on the safe side, if you suspect anything to do with the heart.

The surgery for Pect Minor syndrome is called a Pect Minor Tenotomy. If it has been going on for a long time and physical therapy and self massage doesn't fix the old stuff that has built up, only then would you consider a tenotomy being done by a vascular surgeon who does a lot of those.

A good Physical Therapist who understands TOS well can mobilize the pect minor and teach you to self massage that area with a 5 "diameter ball and it has worked wonders for me and I had a lot of tightness issues with my Pect Minor, prior to that.

With a Tenotomy, you might lose some function of the arm and it may have to be a trade off between pain relief and some function loss.
Some patients on this forum have had a tenotomy, someone might post about their experience.