hey...i've been smoking marijuana since i have 15...and one day i don't know why my body started to have a strange reaction...a strong tachycardia started...really,really fast i think is one of the worst tachycardia that exist...it cause me like a panic attack,but when i wait for like a couple of minutes,my heartbeat starts to decrease getting in a normal rythm...please let me know what is happening to me...i've been looking for answers fo a long time...and i could'nt find no good answers at all...(im not asmanic,no cardiac deseases...nothing) i visit a cardiologist and told me everything was fine...because the heart goes back to normality when the tachycardia stops...i don't know if is the ''THC'' or what?...please let me know... (I AM 18 YEARS OLD,HEIGHT-5'6 WEIGHT-120 pounds.)

Summarized question: What causes tachycardia?