Permanent Junctional Reciprocating Tachycardia (PJRT)

Permanent Junctional Reciprocating Tachycardia (PJRT) is a rare form of incessant supraventricular tachycardia (SVT) caused by a slow-conducting, concealed accessory pathway, typically located in the posterior septum (near the coronary sinus).

PJRT is clinically important because it can produce persistent tachycardia, leading to tachycardia-induced cardiomyopathy, especially in children and young adults.

Primary Reference:

• ESC Supraventricular Tachycardia Guidelines
• Permanent junctional reciprocating tachycardia in infants and Children

PJRT is a form of orthodromic AV reentrant tachycardia (AVRT) utilizing:

• AV node → forward (antegrade) conduction
• A slow, concealed accessory pathway → backward (retrograde) conduction

Because the accessory pathway conducts slowly, the tachycardia:

• Is often incessant (ongoing for hours to days)
• Has a long RP interval
• Has P waves after the QRS, but earlier than in atrial tachycardia

The rhythm is typically 100–200 bpm, slower than typical AVRT.

Key features that distinguish PJRT from other SVTs:

1. Long RP Tachycardia
   • RP interval > PR interval
   • RP is typically long because the retrograde conduction is slow
   • This is the defining ECG hallmark
2. Inverted Retrograde P Waves
   • Seen after the QRS
   • Best visualized in inferior leads (II, III, aVF)
   • Polarity: Negative P waves inferiorly
3. Narrow QRS Complex
   • Because conduction is via the normal His-Purkinje system
4. Regular Rhythm
   • HR usually 110–200 bpm
   • Persistent or “permanent” in many patients
5. Incessant Tachycardia
   • Often constant despite rest or sleep
   • May slow modestly but rarely terminates without intervention
   • Leads to tachycardia-induced cardiomyopathy
6. Pseudo ST-Segment Depression
   • Retrograde P waves can deform the ST segment
   • May mimic ischemia

PJRT is part of the “long-RP tachycardia” family.

PJRT is best identified by the combination of:

• Inverted retrograde P waves
• Long RP interval
• Incessant pattern

Because PJRT is often incessant and causes LV dysfunction, early diagnosis is essential.

• AV nodal blockers (adenosine, beta blockers, calcium channel blockers) may slow but often do not terminate the rhythm
• Adenosine produces VA block but tachycardia usually resumes

• Beta blockers or calcium channel blockers
• Amiodarone or flecainide for refractory cases
• Monitoring for tachycardia-induced cardiomyopathy

• Slow-conducting accessory pathway is ablated
• High cure rate (≈90%)
• Dramatic improvement in LV function once arrhythmia eliminated

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Typical features shown:

• Long RP interval
• Negative retrograde P waves in II, III, aVF
• Narrow QRS
• Regular rhythm

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Notice:

• Retrograde P waves closer to QRS
• RP interval shorter than PJRT

• PJRT is a rare, incessant form of orthodromic AVRT using a slow accessory pathway.
• Characterized by long RP interval, negative retrograde P waves in inferior leads, and regular narrow-complex tachycardia.
• Often leads to tachycardia-induced cardiomyopathy if untreated.
• Catheter ablation is highly effective and often curative.
• Distinguish PJRT from atypical AVNRT and atrial tachycardia by RP interval, P-wave morphology, and incessant pattern.