You may have multiple causes for your symptoms. Lets look at weight gain first. You should discuss this with your cardiologist as some of the meds to decrease irregular heart rhythms can cause or contribute to weight gain, especially beta blockers. The heart ablation may have been incomplete since you are having palpitations again. Since your thyroid is normal, and periods are regular, it s time to see your cardiologist, and if he or she doesn t take this seriously, time to find a new cardiologist. Arrhythmia of the heart can certainly contribute to fatigue since your pump isn t working efficiently. I am assuming you have regular periods. Hormone levels fluctuate over the course of a month, and occasionally the peaks and valleys can be exaggerated,leading to flashes before a period, breast tenderness, more frequent headaches. This will increase in frequency as you age. A few episodes that went away probably isn t relevant. The amount of bleeding you have might fluctuate too. Now the next issue, the history of a chocolate cyst. This is usually a sign of endometriosis, a serious reproductive tract disorder that can be treated to decrease painful menses and preserve fertility. It can cause scarring in the pelvis. Sometimes in severe cases the pelvic organs get so stuck together it is a frozen pelvis.If you don t have pain, and have completed your family then you and your doctor can discuss watching and waiting, but I doubt the disorder resolved with the removal of one ovary. It does not contribute to weight gain, and fatigue, though pain can of course be wearing. I hope this answers your concerns, and helps direct you to a place to start to feel better.Your heart problem should be the first priority to solve.