I have a-fib that among other things can be triggered by drinking. I'm not a heavy drinker, I don't drink daily, but on occasion I will still have a drink or two. Sometimes one drink or half of one of a will start to cause problems for me, at that point I stop. My advice would be to set a limit before you start drinking...say, I can have only 2 drinks. If you start feeling anything before reaching the 2 drink limit, stop! Stay hydrated as well and listen to your body. Do not up your limit...you won't be doing yourself any favors.
"Ease back into drinking"?
It depends on how you define 'drinking.' Here are the U.S. Department of Health guidelines for healthful amounts of alcohol per day for average adults:
"Despite the complexity, numerical definitions of moderate drinking do exist. For example, guidelines put forth jointly by the U.S. Department of Agriculture and the U.S. Department of Health and Human Services (2) define moderate drinking as no more than one drink a day for most women, and no more than two drinks a day for most men. A standard drink is generally considered to be 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of 80-proof distilled spirits. Each of these drinks contains roughly the same amount of absolute alcohol--approximately 0.5 ounce or 12 grams (3)."
So, in terms of roughly 'average' drinking, a healthy man (with no previous cardiac symptoms) should no take in more than 24 ounces of beer or 10 ounces of wine, or 3 oz. of distilled spirits per day.
http://alcoholism.about.com/cs/basics/l/blnaa16.htm
Knowing that, a person can make informed choices about need vs. want.
I don't know what you mean by "social drinking"... if you mean a beer or glass of wine at about 1 per hour and you eat regular meals, I think it should not be a problem relative to your heart rhythm - but, binge drinking is bad for your whole body, so my recommendation is keep it at a "social" level, i.e., not drunk.
I suffer from permanent atrial fibrillation, I am also a senior age person which adds some complications, still if I drink a "few" beer/wine even some hard liquor over a period of 4 or 5 hours I end up neither drunk nor with a heart problem. Some of the medications I take do specify not to drink alcohol, but it hasn't yet caused me any problems at the "social" level.