There are several beta blockers many doctors prescribe for Afib. One should have a complete electrocardiogram.
The process is quite simple. The cardiologist can show you your beating heart on the computer and measure the sizes of the atrium and/or ventricles. My atrium was slightly enlarged, but not out of the range of normal.

I have a modest case, meaning I never a problem with excessive heartbeating. I have been taking Pradaxa and Atenolon now since 2015. As most know, cardioversion (shock treatment) is often done to "set" the heart rate back to normal. Then, the most often option is the ablation process. Lots of subjective analysis with your doctor and best to seek more than one opinion. If you are near several of the best..like Mayo or Cleveland Clinic..do use their services in lieu of the doctor who refers you to another doctor in the "association".