Dear Sir Thanks for your query to HCmagic. A combination of fast heart rate and shakiness favors activation of sympathetic nervous system in your body (a system which is responsible for making to alert/ active/hyperactive). It may get activated in situations of anxiety/ fear/ nervousness/ elation, or by drinking excess of coffee/tea/cocaine/alcohol/ anti-asthma drugs. you have to judge if anything like this was there. If there is an underlying cardiac cause for this? Not possible to tell without an examination. However if you have undue shortness of breath/ blackouts/ loss of consciousness/ Chest pain/ giddiness/ recurrent or increasing symptoms, please see your doctor at priority. Sincerely Sukhvinder Singh