oversensing
Inappropriate detection of electrical signals by a cardiac device, leading to improper therapy delivery or pacing inhibition.
Full Definition
Oversensing occurs when a cardiac device inappropriately detects and responds to electrical signals that are not true cardiac depolarizations. Common causes include T-wave oversensing, muscle artifacts, electromagnetic interference, lead fracture, or loose connections generating noise. In pacemakers, oversensing can lead to inappropriate pacing inhibition and potential asystole. In ICDs, oversensing may trigger unnecessary shock therapy. Modern devices employ various algorithms including morphology analysis, sudden onset detection, and stability criteria to minimize oversensing. Programming adjustments to sensitivity settings, blanking periods, or sensing configuration can often resolve oversensing issues.
Usage
Usage note: Contrast with undersensing in device troubleshooting documentation.
In Context
- "T-wave oversensing was corrected by reducing ventricular sensitivity from 0.3mV to 0.6mV." — Device programming report
- "The inappropriate shocks were attributed to lead fracture causing oversensing of noise." — Device malfunction analysis