Hi. You seem to have got proper evaluation for your father for his symptoms including angiogram. Unlikely that the vaccine is causing symptoms for so long.
Are these palpitation epiosdes associated with high BP? When he feels tired and palpitations is the pulse rate too low prices too high? Could you record? Are other blood tests like
Thyroid, Hb etc normal?
Next Steps
If the palpitations are very frequent and disturbing you can consult your cardiologist and plan a 24 hrs Holter test
Health Tips
Since he is a heart patient it is important for him to get vaccinated. I would suggest complete the vaccination dose under supervision of your doctor.