The answer to your question about how long you will have to be on an anti-coagulant (DOAC in the medical community, means 'direct-acting oral anti-coagulant'):

It depends on your risk for stroke, your sex, and your age. This can be easily computed by you if you know, and are willing to enter, the true values for each of the fields. Try this:
https://www.mdcalc.com/calc/801/cha2ds2-vasc-score-atrial-fibrillation-stroke-risk
If your score is above 2 when all fields are added, you will be strongly advised to take a DOAC, and probably for the rest of your life. You can always decline, but it would be against the advice of a cardiologist who would otherwise prescribe it for you.
Why stroke risk? Because of the nature of the arrhythmia, and due to the anatomy of the typical human heart. This all presupposes that your arrhythmia is atrial fibrillation, which is an electrical disorder of the left atrium. If you have another arrhythmia, you may not have to take a DOAC, but that would be determined with you seeing a cardiologist.