which you have undergone contains one drug called anthracycline. This drug beyond a certain cumulative dose is known to cause some cardiac effects. Rituximab
and chest radiation
have the potentiating effect. So every possiblity of post chemo radio effect leading to arrythmia.
continously is not harmful. The purpose that your cardiologist wanted to stop this medicine was to see if you can do without it. Since the arrythmia recured you can continue to use the drug. There will be no long term side effects.
Dr. J. Ticku