I ate flaxseed months ago and had heart palpitations. now today i ate chia seeds in a recipe and now having heart flutters again. do these cause this?

Possible allergy: I've never heard of either flax or chia seeds causing heart palpitations. This could be a coincidence (just because you eat something and then get a symptom does not mean that was the cause of the symptom). It is possible you are allergic to flax and chia seeds, as palpitations can be caused by food allergies. Try these again (separately).If every time you eat them you get palpitations then avoid.