Overdrive Suppression
The phenomenon where rapid pacing suppresses automaticity in ectopic foci, used to differentiate automatic from reentrant mechanisms.
Full Definition
Overdrive suppression is a physiologic response where rapid pacing at rates faster than an automatic focus temporarily suppresses the intrinsic automaticity of that tissue. Following cessation of overdrive pacing, automatic foci demonstrate a pause before resuming activity, with the pause duration proportional to the pacing rate and duration. This contrasts with reentrant mechanisms, which typically resume immediately after pacing termination. Overdrive suppression testing is valuable for differentiating between automatic and reentrant arrhythmia mechanisms during electrophysiology study. The degree of suppression helps characterize the automaticity and guide therapeutic approaches.
Usage
Usage note: Use as compound term. Distinguished from 'overdrive termination' which applies to reentrant arrhythmias.
In Context
- "Overdrive suppression with a 3-second pause confirmed the automatic mechanism." — Arrhythmia characterization
- "The absence of overdrive suppression suggested a reentrant rather than automatic etiology." — Differential diagnosis report