Loading isn't really necessary as the previous poster has mentioned. 3-5 grams a day is enough. It will take you a little longer to get saturated with this smaller daily dose, but the end result is still the same. I usually don't bother with loading it.
You may want to ask a doctor, although a doctor may not be very aware of creatine supplementation. My guess is that it would not harm you. Creatine monohydrate naturally occurs in red meat so i can't imagine it having a negative effect on your heart.
My latest related article:
Does Creatine Work?