What is the best medicine to take in early stage of pregnancy knowing that she has a heart failure?

If the expecting woman has a heart failure I would assume she is seeing a doctor regularly and she really needs to ask him. Everyone is different and this is certainly not something you can take a chance with. The doctor always need to know if the woman is taking, or plan on taking, any medication when she is pregnant. Medications also interact with each other if she takes more than one.