Palpitations after alcohol/coffee/sometimes even tea...

Hello all,
I am healthy 27yo (70kg/180cm Caucasian) fit guy. for a few years I have been experiencing palpitaitons time to time (like for 5-10 minutes once a month or so, almost exclusively at night before I go to bed). I have seen two cardiologists who both made a echo of my heart and resting ekg and did not find anything wrong with me.
For a few months now I have been experiencing palpitations almost every time I go out and drink alcohol. One glass of wine is enough for the palpitations to occur when I get home and they persist until I fall asleep. The next morning I am ok. The same happens when I drink coffe or drink a lot of green tea.
Just to say, I almost dont drink alcohol and the times I had coffee I could cound on my fingers.

Is this a cause for alarm and further pursuit of diagnosis or are some people just sensive to alcohol/caffeine/tein...?

One other thing that I would not say is connected to this issue and more to my trapped nerve/problems with my trapezius/neck, is that my left hand is sometimes turning blue-ish..

Thanks for any kind of answer.

Best,
Jirka.