Cardiomyopathy

Mickey is a senior 14 lb. Jack Russell and she has been diagnosed with cardiomyopathy (she has a heart murmur and her heart is swollen).  She is doing well at the moment, but we would like to add CoQ10 and maybe L-Carnitine as supplements for her.  But I don't know what dosages would be okay.  Anyone know?  Thank you.