Arrhythmias & electrophysiology
Pacing Related Conduction Delay as an Indicator of Intramural Site of Origin of Focal Ventricular Arrhythmias
Authors' conclusion
Conduction delay with matching PMs but late activation indicates a deeper SOO. A cutoff value of >26 milliseconds between S-QRS and EGM-QRS intervals identified deeper-seated VA target sites. This required further mapping to identify alternative ablation sites. A matching PM may not always be indicative of the SOO in patients with PVCs.
Study context
- Population
- Patients with frequent premature ventricular complexes (PVCs) undergoing activation mapping and pace-mappingconsecutive series of patients with frequent PVCs
- Participants
- 46 patients
- Exposure
- Mismatch between S-QRS and EGM-QRS intervals to distinguish effective from ineffective ablation sites with a matching pace-mapping (PM)
- Outcome
- Matching PMs identified
Methodological detailsconsecutive series
- Consecutive series
Main finding
As reported in the abstract
Ventricular arrhythmias (VAs) with matching PMs
32
Patients with matching PMs
30 of the 46
Observational data: associations, not effects.
Further findings
S-QRS vs EGM-QRS mismatch of >26 milliseconds distinguishing effective from ineffective ablation sites with a matching PM
- Area under the curve
- 0.98; 95% CI: 0.94-1
- Sensitivity
- 100%
- Specificity
- 88.9%
- Receiver operating characteristic analysis at the target site/PVC level
Mismatch present and radiofrequency ablation failure
- Patients with a mismatch
- 9
- Radiofrequency ablation failed, of those with a mismatch
- 8/9
Alternate sites with early activation times without matching PM, where radiofrequency eliminated the PVCs
- Early activation time at alternate sites
- −48.4 ± 37.39 milliseconds
- Identified, of the 8 patients with failed ablation
- 5/8
Original publication
Summarised from the published abstract; every number is checked against it