Hope this is the right place to put this.

I, too, have had the "waking during the night with sob and dizziness." In my case, I do not believe it to be afib, as I have been in different afib situations. I found, upon taking increased doses of Toprol XL, vivid dreams happen more often. Also, when I overdue on any one day, I can expect to wake during the night. I attributed those times to "over-doing" and in a deeper sleep during the night. Could be in such a deep sleep that breathing is too shallow. I really appreciate the "wake-up" call versus not breathing at all.

I find that if I'm overtired and go to bed in a raised position, I do not experience such sob. May work for you, too.

By all means, check with your cardiologist about drug change side-effects.

Hope this has been of some help. Others are sure to add,