Decremental Pathway
An accessory conduction pathway that exhibits rate-dependent slowing of conduction velocity.
Full Definition
A type of accessory pathway characterized by decremental conduction properties, meaning that as the heart rate increases, the conduction velocity through the pathway progressively slows. This is in contrast to typical accessory pathways (like those in Wolff-Parkinson-White syndrome) which maintain constant conduction velocities regardless of heart rate. Decremental pathways are often found in the posteroseptal region and can participate in unusual forms of reciprocating tachycardia. The decremental properties result from specific electrophysiological characteristics of the pathway tissue, similar to AV nodal conduction.
Usage
Usage note: Distinguish from 'decremental conduction' which describes a property, whereas this refers to a specific anatomical structure.
In Context
- "The decremental pathway showed progressive conduction delay with shorter coupling intervals during extrastimulus testing." — EP study interpretation
- "Decremental pathways may be missed on surface ECG due to their rate-dependent conduction properties." — Cardiology review article