atrial refractory period
The programmed time after an atrial event during which the atrial sensing circuit is temporarily disabled.
Full Definition
The atrial refractory period (ARP) is a programmable timing interval during which the pacemaker's atrial sensing circuit is intentionally blanked to prevent inappropriate sensing of signals that should not influence device timing. This period typically begins after either a paced or sensed atrial event and prevents the device from detecting T-waves, far-field ventricular signals, or other artifacts that might otherwise be misinterpreted as atrial activity. The ARP is crucial for proper dual-chamber pacemaker operation, as it helps maintain appropriate atrioventricular synchrony and prevents mode switching due to inappropriate atrial sensing. Optimal programming of the ARP must balance the need to avoid oversensing while ensuring that physiologically relevant atrial activity is not missed, particularly during exercise when atrial rates may be elevated.
Usage
Usage note: Often abbreviated as ARP; distinguish from PVARP (post-ventricular atrial refractory period).
In Context
- "The atrial refractory period was extended to 350 ms to prevent far-field R-wave oversensing." — Device programming note
- "Inappropriate mode switching resolved after optimizing the atrial refractory period settings." — Device troubleshooting report