
Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Junctional bradycardia pathophysiology
Introduction
Overview
Overview
Junctional bradycardia or an AV junctional escape is a delayed heartbeat originating from an ectopic focus somewhere in the AV junction to compensate for an SA node that is no longer handling the pacemaking activity.
Pathophysiology
Pathophysiology
Normally, the atrioventricular node (AVN) can generate an escape rhythm of 40-60 beats per minute in case the sinoatrial node (SA node) or atrial pacemakers fail (sinus arrest) or slow (sinus bradycardia) or if there is complete heart block. This junctional escape rhythm generates a normal, narrow QRS complex rhythm at a rate below 60 beats per minute (junctional bradycardia) as the electrical impulses once they are generated are conducted with normal velocity down the usual pathways. Retrograde P waves (i.e. upside down) P waves due to retrograde or backward conduction may or may not be present.
References
References
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mugilan Poongkunran M.B.B.S [2]
