Background: IART is not uncommon after some of the more complex heart surgeries due to the potential for more extensive atrial scar providing additional arrhythmia substrate.
AEG: Typically, IART has a rapid fixed atrial rate. Atrial rates are often between 200bpm to 350bpm, though rates may be slower in patients with congenital heart disease or diseased myocardium. Depending on the AV nodal conduction IART may show a regular A-V and V-V timing such as seen with 2:1 or 3:1 AV conduction. Our simplified figure demonstrates an IART with 2:1 AV conduction. Alternatively, the AEG may also show an irregular ventricular rate as seen in the patient example.
Adenosine: IART is not adenosine sensitive. Adenosine can be used to more easily view the atrial complexes by blocking the AV nodal conduction and slowing the ventricular rate.
Atrial Overdrive Pacing: IART may be terminated with atrial overdrive pacing.