Usually due to a single abnormally firing focus in the atrium (focal AT)
Unlike AVNRT or AVRT, AT is not dependent on conduction through that AV node.
Adenosine is an effective acute treatment of both AVNRT and AVRT, but is less effective against AT
The mechanism of the development of AT is usually enhanced automaticity or triggered activity but may also include microreentry.
ECG
Long RP tachycardia
Since AT is not dependent on the AV node, it does not usually terminate with AV block, and there may be periods of variable conduction with AV dissociation with more Ps than QRSs.
