Unfortunately, the side effects will probably not abate, and weight gain is indeed a very common side effect. You should speak with your cardiologist about ablation as an option.
By the way, are you just beginning menopause? Many of us with PAT/SVT have found that hormonal fluctuations trigger episodes for us.
Yes, I thought they could be related to menopause. However, I have also read articles about runners and/or athletes with low heart rates developing PAC's or PVC's. Ablation has been recommended as a last resort but it's beginning to feel like a better option than the side effects of the beta blocker.
Ablation need not necessarily be thought of as a last resort. It's a safe procedure and if done by an experienced EP, it has a cure rate of greater than 90%. Having PAT over and done with is pretty appealing compared with fighting medication side effects for years and years.