Junctional tachycardia is a form of

supraventricular tachycardia Supraventricular tachycardia (SVT) is an umbrella term for fast heart rhythms arising from the upper part of the heart. This is in contrast to the other group of fast heart rhythms – ventricular tachycardia, which start within the lower cham ...

characterized by involvement of the

AV node The atrioventricular node or AV node electrically connects the heart's atria and ventricles to coordinate beating in the top of the heart; it is part of the electrical conduction system of the heart. The AV node lies at the lower back section of t ...

. It can be contrasted to

atrial tachycardia Atrial tachycardia is a type of heart rhythm problem in which the heart's electrical impulse comes from an ectopic pacemaker (that is, an abnormally located cardiac pacemaker) in the upper chambers ( atria) of the heart, rather than from the sino ...

. 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. 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. Double tachycardia with captures

Cause

It can be associated with

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toxicity. It may also be due to onset of

acute coronary syndrome Acute coronary syndrome (ACS) is a syndrome (a set of signs and symptoms) due to decreased blood flow in the coronary arteries such that part of the heart muscle is unable to function properly or dies. The most common symptom is centrally loca ...

heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...

, conduction system diseases with enhanced

automaticity Automaticity is the ability to do things without occupying the mind with the low-level details required, allowing it to become an automatic response pattern or habit. It is usually the result of learning, repetition, and practice. Examples of tas ...

, or administration of

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Diagnosis

On an EKG, junctional tachycardia exhibits the following classic criteria: * 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. Forms of junctional tachycardia include

junctional ectopic tachycardia Junctional ectopic tachycardia (JET) is a rare syndrome of the heart that manifests in patients recovering from heart surgery. It is characterized by cardiac arrhythmia, or irregular beating of the heart, caused by abnormal conduction from or thr ...

(JET) and atrioventricular nodal re-entrant tachycardia (AVNRT) which can be distinguished by performing electrophysiological studies.

Treatment

Amiodarone Amiodarone is an antiarrhythmic medication used to treat and prevent a number of types of cardiac dysrhythmias. This includes ventricular tachycardia (VT), ventricular fibrillation (VF), and wide complex tachycardia, as well as atrial fibrilla ...

is used to control the rhythm. Electrical cardioversion is not used.

References

External links

Cardiac arrhythmia {{circulatory-disease-stub

Cause

Diagnosis

Treatment

See also

References

External links