The best advice will be to STOP SMOKING. STOP OR AT LEAST CUT DOWN 'ENERGY DRINK'. They along with anxiety
are the common contributors for palpitation
The blood test
may give some clue - anaemia, thyroid
and the like
Irregular heart beats need to be documented by ElectroCardioGram (ECG). If a routine ECG does not show, 24 or 48 hour ambulatory ECG monitoring (Holter) is done.
is done to see the heart valves, wall and function
You need assessment and assistance from a qualified cardiologist, to rule out an underlying heart condition - which, however, seems not very likely.