My mom recently had a heart attack and cardiac arrest and was revived. the doctor said she had an old heart. what does this mean? can it strengthen?

Damaged muscles: I guess he means the overall condition of her heart doesn't match a normal heart of her age. With each heart attack we lose the strength of some of the muscle. Sometimes its partially reversible, due to collateral circulation that may develop . Needs to be followed closely and maintain her blood pressure and cholesterol below normal range. There are some incidental studies showing benefit of coq10.