Heart issue?

Been drinking for a while, years. Probably 4 ish good years and I drink I lot on the weekends like 10 a day but week days probably 6 or 7 or non and never have withdrawals. I am only 22 and last weekend I was drinking really heavy and noticed I woke up in the middle of the night a few nights in a row with my heart pounding out my chest, maybe irregular heart beat but maybe not? Gave me anxiety and was thinking my heart had a issue but I haven’t drank in couple days and I started drinking a shit ton of water and started taking magnesium. What do y’all think this is? Have never had this issue and am in very very good shape. I must’ve been very dehydrated?