Atrioventricular junction irritability can trigger an impulse rate greater than the AV junction’s inherent rate of 40–60 bpm. When junctional irritability results in a rate of 60–100 bpm, it is called an accelerated junctional rhythm. When the rate exceeds 100 bpm, it is called junctional tachycardia. 

Characteristics of an Accelerated Junctional Rhythm

1. Regular rhythm
2. Rate 60–100 bpm
3. An inverted P wave that manifests before, after, or hidden within the QRS complex
4. A shortened PR interval if the P wave is seen before the QRS complex (< 120 milliseconds)
5. A normal QRS complex (< 120 milliseconds)

Characteristics of Junctional Tachycardia 

1. Regular rhythm
2. Rate is 100–180 bpm
3. An inverted P wave that manifests before, after, or hidden within the QRS complex
4. A shortened PR interval if the P wave is seen before the QRS complex (< 120 milliseconds)
5. A normal QRS complex (< 120 milliseconds)