Junctional tachycardia: Difference between revisions
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==Evaluation== | ==Evaluation== | ||
[[File:Junctional Tachycardia.jpg|thumb|ECG showing junctional tachycardia. Note narrow complex QRS, no P waves, and accelerated rate.]] | |||
*[[ECG]] findings | *[[ECG]] findings | ||
**P waves | **P waves | ||
Revision as of 23:14, 27 February 2021
Background
- Rare
- Cardiac impulses originate at the AV junction
- AV node
- Bundle of His
- Also referred to as Junctional Ectopic Tachycardia (JET) or Congenital Ectopic Tachycardia (CJET) if present at birth
- Rate exceeds the upper limit seen in normal sinus rhythm
- In adults, >100 bpm
- In pediatric patients it varies by age until age 8 or 9 (see pediatric vital signs)
Clinical Features
- Clinical features vary widely, diagnosis usually made via ECG
- Past medical hx may include recent cardiovascular surgery
Differential Diagnosis
Narrow-complex tachycardia
- Regular
- AV Node Independent
- Sinus tachycardia
- Atrial tachycardia (uni-focal or multi-focal)
- Atrial fibrillation
- Atrial flutter
- Idiopathic fascicular left ventricular tachycardia
- AV Node Dependent
- AV Node Independent
- Irregular
- Multifocal atrial tachycardia (MAT)
- Sinus tachycardia with frequent PACs, PJCs, PVCs
- Atrial fibrillation
- Atrial flutter with variable conduction
- Digoxin Toxicity
Wide-complex tachycardia
Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)
- Regular
- Monomorphic ventricular tachycardia
- PSVT with aberrant conduction:
- PSVT with bundle branch block^
- PSVT with accessory pathway
- Atrial flutter with bundle branch block^
- Sinus tachycardia with bundle branch block^
- Accelerated idioventricular rhythm (consider if less than or ~120 bpm)
- Metabolic
- Irregular
- Atrial fibrillation/atrial flutter with variable AV conduction AND bundle branch block^
- Atrial fibrillation/atrial flutter with variable AV conduction AND accessory pathway (e.g. WPW)
- Atrial fibrillation + hyperkalemia
- Polymorphic ventricular tachycardia
^Fixed or rate-related
Evaluation
- ECG findings
- P waves
- may be antegrade, retrograde, or absent depending on depolarization of the atrial relative to the ventricles
- QRS complexes
- Narrow in the absence of aberrancy
- P waves
- May be distinguished from AVNRT via Adenosine administration
- If JET is present, atrial depolarization will briefly terminate and reveal AV dissociation
- If AVNRT is present, conversion to sinus rhythm will likely occur
- Avoid administration in the setting of aberrancy
- JET will concomitant 3 degree AVB is rare
- Consider JET underlying causes to include
- Electrolyte abnormalities
- Acidosis
- Cardiovascular surgery within 24-48 hrs
Management
Synchronized Cardioversion
- Junctional Ectopic Tachycardia is unresponsive to DC shock
Transcutaneous Pacing
- Junctional Ectopic Tachycardia is unresponsive to overdrive pacing
Pharmacological
Amiodarone
- 2 mg/kg bolus.[1]
- if necessary, as continuous infusion at 10 to 15 mug/kg/min
Flecainide
Encainide
Propafenone
Non-Pharmacological
- Catheter ablation
Disposition
- 4-9% mortality rate in CJET
- Refractory JET may require catheter ablation
See Also
External Links
References
- ↑ [pubmed.ncbi.nlm.nih.gov/19632422], Kovacikova L. Amiodarone as a First-Line Therapy for Postoperative Junctional Ectopic Tachycardia. PubMed, National Library of Medicine, Aug 30, 2009.