General Overview

We are about to embark on one of the most complicated topics in arrhythmia recognition, atrioventricular nodal reentry tachycardia (AVNRT). Every time we have approached this topic in any lecture series (including advanced clinicians with years of experience), there is confusion as to the cause, mechanisms, and recognition of this complex but extremely common arrhythmia. Out of those three factors, the mechanisms involved are always the toughest.

In this chapter, we will try to simplify the topic of AVNRT and make the concepts workable so that you can use them in everyday clinical life. To do this, we are going to deviate from our traditional approach and present the topic in a systematic three-step approach:

1. We will explain the process of reentry as it relates to AVNRT in very general, nonmedical terms.
2. We will take those principles and apply them to the AV junction, and to the pathology found in AVNRT in particular.
3. We will present the specifics of the arrhythmia clinically and electrocardiographically.