Junctional bradycardia: Difference between revisions
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*[[Complete heart block]] | *[[Complete heart block]] | ||
*[[Conduction system disease]] | *[[Conduction system disease]] | ||
*[[Digitalis]] | *[[Digitalis toxicity]] | ||
*Healthy response during sleep in patients with heightened vagal tone | *Healthy response during sleep in patients with heightened vagal tone | ||
*[[Heart surgery]] particularly [[valve replacement]] | *[[Heart surgery]] particularly [[valve replacement]] | ||
Revision as of 02:01, 4 September 2012
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: junctional escape; junctional escape rhythm
Overview
Junctional bradycardia is a slow (40 to 60 beats per minute) narrow complex escape rhythm that originates in the atrioventricular node to compensate for slow or impaired conduction of pacemaker activity in the atrium.
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 rte 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.
Causes
- Acute MI
- Complete heart block
- Conduction system disease
- Digitalis toxicity
- Healthy response during sleep in patients with heightened vagal tone
- Heart surgery particularly valve replacement
- Ischemic heart disease
- NSTEMI
- Sinus arrest
- Sinus bradycardia
- STEMI