Arrhythmia is an electrical conduction phenomonon that can be compromised by impaired pathways and tissue damaged of the heart organ causing a disorder of the electrical impulses impeded the contraction of heart chambers. The electrical impulses are generated within the heart and the impulses are confined to the heart.
Any improvement of your arrhythmia would entirely coincidental. There maybe some connection with valve damage due to bacteral infection that gets into the blood stream and settles on a vulnerable valve.