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The Double Fire Phenomenon With Alternating Right Bundle Aberrancy
Anish S Shah1, Marc C Engels2, T Jared Bunch2
1Division of Cardiology, Department of Medicine, University of Utah, Salt Lake City, Utah, USA; Department of Medicine, George E. Wahlen VA Medical Center, Salt Lake City, Utah, USA.
JACC. Case Reports
|July 30, 2026
Summary
Dual AV nodal non-reentrant tachycardia is an uncommon arrhythmia. It can occur in patients with dual AV nodal physiology, especially after slow pathway modification for AV nodal reentrant tachycardia.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- The atrioventricular (AV) node's complex structure enables various atrial and ventricular arrhythmias.
- Dual AV nodal physiology can lead to complex tachycardias.
Purpose of the Study:
- To describe a case of dual AV nodal non-reentrant tachycardia.
- To highlight the importance of ECG in diagnosing complex arrhythmias.
Main Methods:
- A patient with supraventricular tachycardias underwent ablation for AVNRT and orthodromic reciprocating tachycardia.
- Electrophysiology study revealed dual AV nodal physiology with conduction down both fast and slow pathways.
- Further slow pathway modification was performed.
Main Results:
- The patient experienced symptomatic tachycardias despite initial ablation.
- ECG showed a regularly irregular tachycardia with narrow and wide complexes.
- Post-ablation, no further arrhythmias were observed.
Conclusions:
- Dual AV nodal non-reentrant tachycardia is rare but can arise in patients with dual AV nodal physiology.
- This arrhythmia may occur after slow pathway modification for AVNRT.
- ECG analysis of P wave to QRS relationships is crucial for diagnosing complex arrhythmias.
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