firstly please specify your age your smoking habits your weight palpitstions can be because of many causes ..as your palpitation comes off and goes away an ecg should be taken out during that cycle if possible if not then at first go for these few investigations Holter monitoring this test is like a ecg taken for 24hours continously ...it will record any abnormal beat during 24hours a loop monitor if required (as you have not mentioned frequency of your palpitations)a loop monitor is like holter but it record beats for 1week tmt (tread mill test) it will serve dual purpose ..it will record any lack of blood supply to the heart (some times you have pain in chest ) and any abnormal beats arising during the couse of doing it apart from this thyroid profile should be done! these symptoms can be because of heart burn gastritis and anxiety so a detailed history is required dizziness on standing up is called orthostatic hypotension(please specify if you are on anti hypertensive medication especially diuretic) how long does it last any history of fall or loss of consciousness as we have to rule out presyncope from orthostatic hypotension thanks