James fibers

Jump to navigation Jump to search

WikiDoc Resources for James fibers


Most recent articles on James fibers

Most cited articles on James fibers

Review articles on James fibers

Articles on James fibers in N Eng J Med, Lancet, BMJ


Powerpoint slides on James fibers

Images of James fibers

Photos of James fibers

Podcasts & MP3s on James fibers

Videos on James fibers

Evidence Based Medicine

Cochrane Collaboration on James fibers

Bandolier on James fibers

TRIP on James fibers

Clinical Trials

Ongoing Trials on James fibers at Clinical Trials.gov

Trial results on James fibers

Clinical Trials on James fibers at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on James fibers

NICE Guidance on James fibers


FDA on James fibers

CDC on James fibers


Books on James fibers


James fibers in the news

Be alerted to news on James fibers

News trends on James fibers


Blogs on James fibers


Definitions of James fibers

Patient Resources / Community

Patient resources on James fibers

Discussion groups on James fibers

Patient Handouts on James fibers

Directions to Hospitals Treating James fibers

Risk calculators and risk factors for James fibers

Healthcare Provider Resources

Symptoms of James fibers

Causes & Risk Factors for James fibers

Diagnostic studies for James fibers

Treatment of James fibers

Continuing Medical Education (CME)

CME Programs on James fibers


James fibers en Espanol

James fibers en Francais


James fibers in the Marketplace

Patents on James fibers

Experimental / Informatics

List of terms related to James fibers

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vendhan Ramanujam M.B.B.S [2]

Synonyms and keywords: Atrioventricular bypass fibers


James fibers are otherwise known as atrioventricular bypass fibers that connect the atrial fibers to bundle of His by penetrating through the AV node. These fibers are categorized as fibers that bypass through the normal conducting system.[1][2]

Historical Perspective

Accessory bypass fibers connecting the atrial fibers to bundle of His by penetrating through the AV node was first described by James in 1961.[3]


James fibers originate in the low atrium and terminate in the low AV node. They connect the above atrial fibers with the below bundle of His. While penetrating the AV node, these fibers run as posterior internodal tract along with other fibers but make contact with the node more distally than the other posterior input fibers. Since they never completely bypass the AV node and found to exist in all hearts, he also described that these fibers may not be actual accessory fibers as we assume. They do not share the rate-slowing properties of the AV node, and may conduct electrical activity at a significantly higher rate than the AV node. This rapid conduction can lead to improper ventricular filling and emptying making the body hemodynamically unstable. If not corrected quickly, the ventricles can fibrillate causing ventricular fibrillation and sudden cardiac death.

Conditions Involving James Fibers

Conduction through James fibers is one of the possibilities for a short PR interval in Lown-Ganong-Levine syndrome. Since these fibers pass through the normal conduction system, QRS complex following the short PR interval in LGL syndrome is found to be normal thus differentiating it from Wolff-Parkinson-White syndrome where the QRS complex is found to be wide and bizzare.


When medical therapy fails while treating LGL syndrome, which is rare, radiofrequency ablation of AV node and its accessory fibers may be considered.


  1. Rossi L (1975). "A histological survey of pre-excitation syndrome and related arrhythmias". G Ital Cardiol. 5 (6): 816–28. PMID 1222879.
  2. Anderson RH, Becker AE, Brechenmacher C, Davies MJ, Rossi L (1975). "Ventricular preexcitation. A proposed nomenclature for its substrates". Eur J Cardiol. 3 (1): 27–36. PMID 1132407. Unknown parameter |month= ignored (help)
  3. JAMES TN (1961). "Morphology of the human atrioventricular node, with remarks pertinent to its electrophysiology". Am. Heart J. 62: 756–71. PMID 14451029. Unknown parameter |month= ignored (help)

See also

Template:WH Template:WS