Hello. Welcome to HCM.
I have read your question and understand your concerns.
Palpitations can be seen even during
stress or excitement. It can be heared in thin individuals as a normal variant. But it can occur in rhythm disturbances of heart and some valvular disorders.
But as you have mentioned already that all the test have been done already and no major cause has been found then you don't need to think much.
Kindly reconfirm that your cardiologist has done holter monitoring (24 hrs ecg monitoring) or not. Most of the time simple missed beats can give rise to palpitations which are non dangerous. So if holter hasn't been done then go for holter monitoring.
2d echo is another very useful investigation to ruleout any valvular pathology.
If all cardiac check up has been done then you don't have to worry much regarding palpitations.
During episodes of palpitations just calm down and divert your mind. Don't do exertion during palpitations. The symptoms subsides on their own usually..
There are medicines available for palpitations like tab
propranolol, but a written prescription from your doctor is required.
Thank you
Have a nice day.