CO Q 10 for improved heart function

Hi All: Just wanted to ask those of you out there what dosage you use if you take CO Q 10 supplement for improving heart function. My Onc. is trying to get my ins. co. to approve starting herceptin again for me. The last time I used Herceptin I had to quit after a couple of months because of heart damage. We think it was due to having A/C so close to the Herceptin/Taxol. I figured I would stack the deck in my favor by trying to strenghthen my heart by starting the CO Q 10 now while we await the decision from the insurance co. but I don't know how much to take. Any info would be great! Thanks, Linda in Calif.