hmmm, TIA? i dont think that it is likely, for loss of consciousness ot occur, it would have to affect the reticular formation.
as for Vasovagal attack, its not common to have palpitations with it, and the nausea, pallor and diaphoresis can differentiate between it and arrhythmia.
so i guess its the arrhythmia guys and as dr nadir said, a holter and an echo would be great i guess.
there is no history of caffiene intake nadir, thats MCQs talking, remember that we drink tea more