Atrial fibrillation and a corresponding enlargement of the left atrium may cause an increase in size of the mitral valve annulus. With a sinus rhythm, the mitral annulus undergoes dynamic changes during the cardiac cycle. For example, at the end of diastole the annular area is smaller than at the end of systole.
To determine who can perform aquatic therapy, we must define what aquatic therapy is. First, notice that aquatic therapy is considered a therapeutic procedure, not a modality. There are many technical and practical distinctions between the practice of aquatic therapy and the application of therapeutic modalities.
Some suggest that a weekly pool shocking should be performed. But such a general timetable would be hard to apply to all pools, in all situations. Referring again to our A-B-C's of pool shocking, there can be only 3 reasons to shock the pool. You either have Algae, Bacteria or Chloramines (and sometimes cloudy water). If you don't see any algae, and your tests for bacteria and chloramines are not concerning, then you can keep the pool shock on the shelf.