Atrial Fibrillation (AFib) Support Group
Atrial fibrillation (AF or afib) is an abnormal heart rhythm (cardiac arrhythmia) which involves the two small, upper heart chambers (the atria). Heart beats in a normal heart begin after electricity generated in the atria by the sinoatrial node spread through the heart and cause contraction of the heart muscle and pumping of blood.

What next? Afib and drinking water? Hey wait a minute... :-)
Keep in mind that I'm 64 years old and have been exercising in the gym 3 times a week, 3 hours a day all of my adult life. Other than afib, I'm in generally good health and take 25 mg metropol per day. I have had afib at some level, since my 20's, although my episodes are nowhere near as bad as what I read here on the forum. I usually can ignore my episodes which tend to last a 10 minutes to 2-3 hours. My heart rate does not go over 130 at rest. I can have episodes daily, or sometimes not for a week or two.
The question became "does the use of a hot whirlpool and sauna affect my afib?" Three different types of health care professionals have suggested to me that the absorption of chlorine from the hot whirlpool (which I used after my exercise routine, so I would be somewhat dehydrated to begin with, causing my skin to possibly absorb more) was disrupting my heart rhythm.
I had noticed that I often had afib episodes on Saturday evening and was often weak and unbalanced on Sunday morning. I use one gym on Monday/Wednesday which does not have a whirlpool or sauna. My Saturday gym has a whirlpool and sauna which I use.
Week one: I forgot my bathing suit, so no whirlpool or sauna. Saturday evening and Sunday morning I was fine.
Week two: I used the sauna only. Had a minor afib episode Saturday evening and was weak Sunday morning;
Week three: Avoided both the sauna and the whirlpool. Was fine Saturday evening and Sunday morning.
Preliminary conclusions: While the chlorine may be contributing to my afib, I'm beginning to suspect that the heat and the dehydration have a major role. I'm always noticed the my afib is MUCH WORSE in summertime. I'm going to work on maintaining hydration (and avoiding the sauna and whirlpool), and report back again in a few weeks. BTW: I found serveral articles that point to dehydration as an afib trigger.
Lately i have been taking my blood pressure in the morning and evening. My morning blood pressure has been way too low. I have since eliminated the COQ10, since that can potentiate my metoprolol. Since eliminating the COQ10, my blood pressure has been more normal.