i don t know exactly whats exactly happening to me.. all of a sudden my heart rate increases radically and my breath get shorten(not all the time).. sometimes its random .. sometimes its after smoking a cigarette .. the attack takes from 5~30 mins with my heart rate going ups and downs also i noticed that my heartbeat is not just faster but it seems stronger.. i went to a doctor and he prescribed Concor COR 2.5,.. at first i didn t want to take it as i am 20 years old and this medicine is taken by 40+ patients with high blood pressure(I ve searched the medicine, Bisoprolol to be exact and what it does).... after a couple of weeks from visiting the doc. the attacks happened frequently so i started to take concor.. helped a lot, but just lowers my daily activity, i feel am not just active as i am normally.. but i increase the shortness in breath, so I ve started taking Minophylline[Theophylline anhydrous] without doc prescription but it solved the issue am having .. I have ECHO CARDIO papers if you want to see them.. but due to am living in Egypt, i really don t trust doc. judgments and conclusions, its really sort-of rare to find a good doc without paying tons of money and searching here and there, and a lot of people are just misdiagnosed ... whats so ever, currently am under a heavy load of pressure and anxiety,.. i think its what makes that elevated heart rate .. i think its a psychic problem not a heart of lung problem.. Also me as a person, i really hate medicine really, i think since i was 10yr i never took any medicine, even thou if i am sick, i usually heal fast without medication and my immune system is good.. also i take really low amounts of sugar, which i think is a good thing, i just don t like sugar and it feels unhealthy .. a few things to mention: 1- i consume lots of caffine(turkish coffee) 2- i am a heavy smoker(sometimes if result in this problem, but it start with the shortness in breath, and follows the increase heart rate) 3- i used to smoke lots of hash, never made me feel sick or bad, but from the moment this condition started, i stopped smoking it immediately as the lowest doses increase my heart rate too much.. finally, i just wanted to mention all of the things that may result in this condition, i hope anyone could give me a logical explanation of why this in happening, this has started from about 3 months and never stopped until now ..! sometimes it happens even if i took my medication... i never had any heart problems never, even under sporty conditions like running or heavy lifting .. thanks in advance....