Is long qt condition inherited or can be acquired? i've had 2 times in the past episodes of very fast, irregular heartbeat. tests ok, no holter test.

NothingOnTheQ-THere: Yes, it can be inherited and yes, it can be acquired (several medications can do it). I'm assuming that one of the "tests" you had was an EKG (test of the heart's electrical conduction system; they attach you to a bunch of wires and the result looks like a bunch of squiggly lines on graph paper). The EKG would tell you if the Q-T is too long. The Holter would be a good idea too, whatever the Q-T.