Treatment Options for Atrial Tachycardia

I recently had a 7 day heart monitor in place and results showed at least 8 episodes of atrial tachycardia, highest number was 139 from a low of 40 bpm.
Looking at the causes I can see stress (constantly high due to family problems) and history of heart disease plus stent placement which I have since 2013 are probably my culprits. I am now 70, also had a bilateral mastectomy in May. Does anyone have experience with this heart arrhythmia? Treatment options? It mostly occurs while I am sleeping and occasionally I feel palpitations...nothing else. I am already on a couple of heart & B/P medications. Kind thanks to anyone in my shoes who wishes to respond.