Junctional tachycardia(JT) is often a misunderstood arrhythmia. Technically, any tachycardia arising from the AV junction could be termed as JT.Even AVNRT was considered as a form of Junctional tachycardia till recently.The crux of the issue is , true anatomical extent and borders of so called AV junction is yet to be clearly demarcated .The common perception that AV node is a discrete structure is an anatomical illusion , rather its collection of condensed fibers with proximal nodal approach and distal fanning .
Now , we have a proper definition by the apex scientific bodies ACC/AHA/HRS 2015)
Source :2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia: Executive summary A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society April 2016Volume 13, Issue 4, Pages e92–e135
Please note :The key point is , JT by definition should be a focal /automatic tachycardia either due to triggered activity or after depolarisation and the boundaries of junctional tissue is liberally extended up to His bundle.
Read related post :What does the term junctional tachycardia mean in current era?
Reference
http://www.heartrhythmjournal.com/article/S1547-5271%2815%2901188-1/pdf
Dr.S.Venkatesan MD 