Advanced
Technical
IVT
capture threshold
The minimum electrical energy required to consistently stimulate myocardial contraction through a pacing lead.
Full Definition
Capture threshold represents the lowest amplitude of electrical stimulation that reliably produces myocardial depolarization and contraction. It is typically measured in volts or milliamperes and varies based on lead position, tissue contact, and time since implantation. The threshold tends to be higher immediately after implantation due to tissue inflammation, then decreases and stabilizes over 6-12 weeks. Programming the pacing output with adequate safety margin above the threshold ensures reliable pacing while preserving battery life.
Usage
Usage note: Always specify units and pulse width when reporting threshold values.
In Context
- "Capture threshold testing revealed a stable value of 0.7 volts at 0.5 ms pulse width." — Device interrogation report
- "Rising capture thresholds may indicate lead maturation, fibrosis, or lead displacement." — Technical training material
Also known as
pacing threshold
stimulation threshold
Don't confuse with
sensing threshold
lead impedance