Junctional tachycardia

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Junctional tachycardia
Junctional Tachycardia.jpg
ECG showing junctional tachycardia. Narrow complex QRS. No P waves. Heart rate fast.
TreatmentAmiodarone to control the rhythm, electrical cardioversion is not used.

Junctional tachycardia is a form of supraventricular tachycardia characterized by involvement of the AV node.[1] It can be contrasted to atrial tachycardia. It is a tachycardia associated with the generation of impulses in a focus in the region of the atrioventricular node due to an A-V disassociation.[2] In general, the AV junction's intrinsic rate is 40-60 bpm so an accelerated junctional rhythm is from 60-100bpm and then becomes junctional tachycardia at a rate of >100 bpm.

Junctional tachycardia (rate about 115/min) dissociated from a slightly slower sinus tachycardia (rate about 107/min) producing one form of double tachycardia; pairs of ventricular capture (C) beats (5th, 6th, 19th, and 20th beats); see laddergram.

Cause[edit]

It can be associated with digitalis toxicity.[3] It may also be due to onset of acute coronary syndrome, heart failure, conduction system diseases with enhanced automaticity, or administration of theophylline.[4]

Diagnosis[edit]

On an EKG, junctional tachycardia exhibits the following classic criteria:[2]

  • P-Waves: The p-wave may be inverted in leads II, III and aVF or may not be visible
  • Narrow QRS complexes (which is consistent with arrhythmias that conduct through the ventricles using the His-Purkinje system and often originate from the atria or AV junction.)

It can coexist with other superventricular tachycardias due to the disassociation between the SA node and the AV node.[citation needed]

Forms of junctional tachycardia include junctional ectopic tachycardia (JET) and atrioventricular nodal re-entrant tachycardia (AVNRT) which can be distinguished by performing electrophysiological studies.[5]

Treatment[edit]

Amiodarone is used to control the rhythm. Electrical cardioversion is not used.[citation needed]

See also[edit]

References[edit]

  1. ^ "junctional tachycardia" at Dorland's Medical Dictionary
  2. ^ a b ROSEN, KENNETH (1973). "Junctional Tachycardia: Mechanisms, Diagnosis, Differential Diagnosis, and Management" (PDF). Circulation. 47 (3): 654–664. doi:10.1161/01.CIR.47.3.654. PMID 4571060. Retrieved March 1, 2015.
  3. ^ "Junctional Rhythm: Overview - eMedicine". Retrieved 2008-12-21.
  4. ^ Aehlert, Barbara (2013). ECGs Made Easy (5th ed.). Elsevier. p. 160. ISBN 9780323170574.
  5. ^ Srivathsan K, Gami AS, Barrett R, Monahan K, Packer DL, Asirvatham SJ (January 2008). "Differentiating atrioventricular nodal reentrant tachycardia from junctional tachycardia: novel application of the delta H-A interval". J. Cardiovasc. Electrophysiol. 19 (1): 071004055652013––. doi:10.1111/j.1540-8167.2007.00961.x. PMID 17916156.

External links[edit]