junctional rhythm
A cardiac rhythm originating from the atrioventricular junction when the sinus node fails to pace effectively.
Full Definition
A junctional rhythm is a cardiac arrhythmia that originates from the atrioventricular (AV) junction, specifically the AV node or bundle of His, when the normal sinus node either fails to generate impulses or these impulses fail to conduct properly. This escape rhythm typically has a rate of 40-60 beats per minute and may present with narrow QRS complexes. P waves may be absent, inverted, or occur after the QRS complex depending on the exact location of the pacemaker within the junction. Junctional rhythms can be seen in various conditions including sinus node dysfunction, increased vagal tone, digitalis toxicity, or ischemic heart disease. While often benign, prolonged junctional rhythms may require treatment if hemodynamically significant.
Usage
Usage note: Specify rate and P wave morphology when documenting; distinguish from other bradyarrhythmias.
In Context
- "The patient developed junctional rhythm with a ventricular rate of 45 bpm following beta-blocker administration." — Cardiac monitoring report
- "Junctional rhythm was noted on telemetry with retrograde P waves visible after each QRS complex." — Cardiology consultation