I understand your concern Vicki. I finished chemo last year and a few months later was told that I had cardiomyopathy. My GP is great and when I began having dizziness etc she sent me for a review with a cardiologist. He diagnosed the problem and then referred me to a specialist cardiologist who has more background in dealing with heart failure and problems from chemo.
I have been told that cardiomyopathy caused by herceptin is usually reversible however for me it seems that it may be more likely caused by AC or Taxol which is a little more challenging.
I've been reassured by my cardiologists that there is still plenty that can be done to improve our heart function post chemo so maybe you could ask to see a cardiologist yourself so that you can get the answers you need from someone who specialises in the area.
Good luck with you quest for answers. I would be happy to chat to you anytime you like.
Polly