Aberrancy
Aberrancy refers to supraventricular impulses that conduct through the His–Purkinje system with delayed or altered intraventricular conduction, producing a wide QRS complex that mimics ventricular tachycardia.
Mechanism
A premature atrial or junctional impulse arrives when one bundle branch is still refractory, forcing conduction down the other branch and creating a functional bundle branch block pattern.
Clinical Significance
Aberrancy is a major cause of wide complex tachycardias that are not ventricular in origin. Distinguishing aberrancy from VT is essential but often mismanaged.
Pitfalls
- Mistaking aberrancy for VT (or vice versa).
- Assuming RBBB morphology = benign.
- Forgetting that rate related aberrancy can occur in AF with RVR.
Related Terms
- Ventricular capture
- Fusion beats
- Bundle branch block
