Cardiac arrhitmia?

I've been having cardiac arrhitmias since I am 13 years old. About 250 bpm and sometimes less. Diagnosis was an anomaly in the mitral valve of my heart Currently I am 30 and I am on medication "amiodarone" to control my heart beats. Doctors said it is a condition that might dissapear after 18 but my last arrhitmia was 1 year ago. Is there any way to get rid of this condition or is it for life?