post-pacing interval
Also written as: PPI — Post-Pacing Interval
The interval from the last pacing stimulus to the next local electrogram during entrainment mapping, used to determine proximity to the reentrant circuit.
Full Definition
The post-pacing interval (PPI) is a crucial measurement during entrainment mapping of reentrant arrhythmias. It represents the time from the last pacing stimulus to the next spontaneous local electrogram at the pacing site after cessation of entrainment pacing. When the PPI equals the tachycardia cycle length (within 30 ms), the pacing site is located within or very close to the reentrant circuit. A significantly longer PPI indicates that the pacing site is a bystander location outside the critical circuit. This measurement helps distinguish between sites that are essential to the reentrant circuit versus those that are passively activated.
Usage
Usage note: Commonly abbreviated as PPI; key measurement for entrainment mapping interpretation.
In Context
- "The post-pacing interval of 385 ms matched the ventricular tachycardia cycle length of 380 ms, confirming the site was within the reentrant circuit." — Entrainment mapping results
- "A prolonged post-pacing interval of 450 ms during a VT cycle length of 350 ms indicated the catheter was in a bystander region." — Mapping interpretation