hi my name shrey from egypt 22 years start palpitation at 16 i awlwys over stress and icrease until 21 went to physician give me concor cor 2.5mg and made ecg it was sinus tacky cardia it was good until i take 7.5mg and problem start tacky cardia and extra syatole sever palpiataion not respond i very nervous and irritable i dont want any drug any more help me plz some people advise me to do echo i afraid of every thing