For those of us that have structurally normal hearts yet are effected by palpitations/tachycardia/fibrillation/flutter/et al, I have been unable to answer the question - is your heart behaving appropriately to the stimulus it gets or is the stimulus normal and your heart acting inappropriately. As everyones symptoms are of the heart acting abnormally its quite easy to initially believe that the root cause is the heart.
Based on my personal cause and effect analysis of my symptoms (for over 23 years) together with my layman understanding of many of the posts on this site, the fact that these symptoms often come and go for no conclusive reason and that they can occur in many areas of the heart causing different symptoms, I have come to a tentative conclusion that it is the stimulus to the heart (not the heart itself) that is the root cause of the problem. Specifically, it is primarily the heart reacting to the inappropriate flow of sodium, calcium and potassium ions caused by abnormal stimulus either by the vagus/sympathetic/parasympathetic nerves or electrolyte imbalance (Sodium, Calcium, Potassium, Magnesium, Iron).
As this is a personal theory only (there are no clinical trials to back it up), I would like to ask the good people on this site, who actually experience the symptoms first hand and are therefore in many way the "experts" for their views or comments (definition of an expert is someone that knows as much as you and just a little more). This is not a theory I feel precious about and would welcome anyone who can pick flaws in it or better still anyone that can offer reasons to accept it.
Unfortunately I cannot offer any fixes but at least if we can get to the bottom of the root cause, there is hope to fixing it rather than continuing trying to just controlling the symptoms of the heart through drugs or ablating.