I've been prescribed topamax (topiramate) and i'm terrified to try it bc i've heard bad side effects. will it effect my irregular heart beat ?

Consult needed!: Does the Dr know of your heart Hx? You need to be very clear about this and seek safer alternatives - they exist. Find a 2nd source if they seem unconcerned. You're right to be very careful. I'll try to refer you to a neurologist here. We have several good ones. Try Dr Saghafi - Ill look for other names if possible. You look near you!