dear, Cardiac arrhythmias could have been a cause of missed pulse or irregularities in beats. However, a normal 24 hour ecg have ruled out this concern of yours. therefore nothing abnoprmal with your heart it confirms. Now regarding your complaints, it could be an psychological anxiety that you could be suffering from. before making any diagnosis I would need some more information from you 1) do you feel palpitations on certain circumstances or on certain thoughts or for whole day? 2) how is your mood keeping these days? 3) do you also experience nausea, dizziness while such episodes? 4) are there specific conditions or circumstances that triggers such symptoms? 5) do you feel tired and not interested in activities nowadays? waiting for your replies... thanks