Arrhythmias & electrophysiology
Very slow atrioventricular nodal reentry masquerading as junctional rhythm: Diagnostic challenges and mechanistic insights
Authors' conclusion
Clinically apparent JRs are often very slow AVNRT in patients referred for ablation. The mechanism of AVNRT initiation with isorhythmic dissociation with sinus rhythm may be concurrent JR and AVNRT or 2-for-1 atrioventricular nodal conduction and AVNRT competing with sinus rhythm.
Study context
- Population
- Patients undergoing AVNRT ablation at Ascension St. Vincent Hospital, Indianapolis, July 2016 to June 2024, with tachycardia cycle length ≥500 mspatients with tachycardia cycle length (TCL) of ≥500 ms among 556 AVNRT ablations
- Participants
- 22 patients
- Outcome
- Clinical diagnosis of JR
Methodological detailssingle-centre
- Single-centre
Main finding
As reported in the abstract
- Clinically diagnosed as having junctional rhythm (JR)
- Nine
- Initiation with junctional beats
- 4
- Apparent accelerating JR merging into sinus rhythm
- 3
- Slow tachycardia rates at 70-110 beats/min
- 8
- Incessant slow tachycardia with simultaneous atrial and ventricular activation on ICD interrogation
- 1
- Of these 9 patients with JR diagnosis, also had a supraventricular tachycardia diagnosis
- Five
Observational data: associations, not effects.
Further findings
His-refractory premature atrial complex perturbing the next His signal
- Confirmed AVNRT in all cases
- all 22
Tachycardia cycle length
- Mean TCL
- 578 ms (range, 500-670 ms)
Initiation with junctional beats and isorhythmic dissociation with sinus rhythm at onset of AVNRT
- Patients each
- Two
Radiofrequency ablation success (slow pathway modified, AVNRT eliminated)
- AVNRT eliminated
- 21 of 22
Original publication
Very slow atrioventricular nodal reentry masquerading as junctional rhythm: Diagnostic challenges and mechanistic insights. Heart Rhythm. Published 23 June 2025. doi:10.
Summarised from the published abstract; every number is checked against it