Joan, you might also want to do some research on the benefits of a supplement known as Coenzyme Q10. A number of women on this site take it as a protectant for their hearts while on Herceptin, and it's also been shown to actually help repair damage caused by congestive heart disease/failure. Here's a link to one site which helps explain how the enzyme works in the body, and cites some of the studies which have been done on CoQ10.
Introduction To Coenzyme Q10
http://faculty.washington.edu/~ely/coenzq10.html
<3 Lolly