effective refractory period
Also written as: ERP — Effective Refractory Period
The longest coupling interval at which a premature stimulus fails to propagate through cardiac tissue.
Full Definition
The effective refractory period (ERP) is the longest coupling interval between a basic drive stimulus and a premature test stimulus at which the premature stimulus fails to conduct through the tissue being studied. This electrophysiologic parameter represents the minimum recovery time required before cardiac tissue can respond to a new electrical stimulus with propagated conduction. ERP varies with cycle length, autonomic tone, and medications. Measurement of ERP is fundamental to electrophysiologic testing and helps assess arrhythmia susceptibility, drug effects, and optimal pacing parameters. ERP is typically shorter than the functional refractory period.
Usage
Usage note: Commonly abbreviated as ERP; distinguish from functional refractory period (FRP).
In Context
- "The atrial effective refractory period was measured at 220 milliseconds during electrophysiology study." — EPS protocol measurements
- "Procainamide prolonged the ventricular effective refractory period from 250 to 310 milliseconds." — Drug effect assessment