Permanent junctional reciprocating tachycardia (PJRT)

Patient

14-year-old adolescent, asymptomatic; evidence of tachycardia during a systematic examination;

Trace

Tachycardia of 150 bpm with narrow QRS; there is a 1:1 ratio between atria and ventricles; atrial activity is positive in aVR and negative in the inferior leads which allows eliminating a sinus tachycardia and suggests a retrograde activation; the RP' interval is longer than the P'R interval; the various possible hypotheses are: reentry due to accessory pathway, an atypical intranodal reentry (fast-slow type) or an atrial tachycardia/flutter with 1:1 conduction;

Trace

This tracing was recorded after the previous tracing; the same initial tachycardia can be seen with a spontaneous termination (blocked on a QRS, no atrial activation); resumption of a sinus activity over 2 complexes (the ECG pattern appears normal on these 2 complexes); resumption of the same tachycardia without evidence of a triggering factor;

Exergue

Permanent junctional reciprocating tachycardias are often chronic, intermittent or permanent; retrograde conduction to the atrium via the accessory pathway is slow and decremental; during the tachycardia, the QRS complexes are generally narrow, the P'R interval short and the RP' interval long; on the sinus complexes, the QRS is narrow without pre-excitation pattern;