Junctional Bradycardia

A junctional bradycardia is a regular rhythm initiated in the AV nodal tissue and occurs when the SA nodal pacemaker fails. This ‘escape’ rhythm is characteristically 40-60 bpm and has a narrow complex (see ECG, below).

This ECG shows a high junctional bradycardia in the setting of an acute coronary syndrome. Click the ECG to see a larger version.

Fig.4 Junctional Rhythm via St. Emlyn’s ECG library

It is not usually a physiological response; causes of junctional bradycardias are listed on the Context page. It can occur during cardiac reperfusion.

It may present as a coincidental finding or with symptoms related to the bradycardia.


Treatment is required if there is haemodynamic compromise: identify causative factors and correct if possible. First line pharmacological treatment is intravenous atropine (0.5 mg).

Prognosis is usually good but in persistent cases permanent pacing may be required.