sensing amplitude
The voltage magnitude of intrinsic cardiac signals detected by pacemaker or ICD leads.
Full Definition
Sensing amplitude quantifies the electrical signal strength that pacemaker and ICD leads detect from intrinsic cardiac activity, typically measured in millivolts during device interrogation. Adequate sensing amplitude is crucial for proper device function, as insufficient amplitude may result in undersensing (failure to detect intrinsic beats), while excessive sensitivity settings may cause oversensing of non-cardiac signals. Normal sensing amplitudes vary by chamber and lead position, with atrial signals typically ranging 1-5mV and ventricular signals 5-20mV. Factors affecting sensing include lead position, tissue maturation, medications, electrolyte imbalances, and lead integrity. Regular monitoring ensures appropriate sensing thresholds with adequate safety margins.
Usage
Usage note: Always specify units (millivolts); distinguish from pacing output measurements.
In Context
- "Ventricular sensing amplitude measured 12.5mV with sensitivity programmed to 2.5mV." — Device parameter check report
- "Declining atrial sensing amplitude may require lead revision or sensitivity adjustment." — Device clinic follow-up note