ABC of clinical electrocardiography: Junctional tachycardias

doi:10.1136/bmj.324.7338.662

BMJ 2002;324:662-665 ( 16 March )

Clinical review

ABC of clinical electrocardiography

Junctional tachycardias

Demas Esberger, Sallyann Jones, Francis Morris.

The first 150 words of the full text of this article appear below.

Any tachyarrhythmia arising from the atria or the atrioventricular junction is a supraventricular tachycardia. In clinicalpractice, however, the term supraventricular tachycardia is reservedfor atrial tachycardias and arrhythmias arising from the regionof the atrioventricular junction as a result of a re-entry mechanism(junctional tachycardias). The most common junctional tachycardiasare atrioventricular nodal re-entrant tachycardia and atrioventricularre-entrant tachycardia.

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Atrioventricular nodal re-entrant tachycardia

This is the most common cause of paroxysmal regular narrow complex tachycardia. Affected individuals are usually young andhealthy with no organic heartdisease.

Mechanism
In atrioventricular nodal re-entrant tachycardiathere are two functionally and anatomically different distinctpathways in the atrioventricular node, with different conductionvelocities and different refractory periods. They share a finalcommon pathway through the lower part of the atrioventricularnode and bundle of His. One pathway is relatively fast and hasa long refractory period; the other pathway is slow with a shortrefractory period. . . . [Full text of this article]