AV nodal reentry tachycardia

AV nodal reentry tachycardia (AVNRT) is caused by the presence of an additional electrical pathway in the AV node, which forms a reentry circuit in the AV node. On the ECG there are fast, narrow, regular QRS complexes without normal P-waves. In some leads, small P-waves may be visible at the end of the QRS complex (retrograde P).

AVNRT can often be terminated by vagal manoeuvres or adenosine. Some patients can be managed by only performing vagal manoeuvres when they feel the AVNRT. Others require antiarrhythmic treatment with beta blockers, verapamil, or flecainide.