Heart failure & cardiomyopathies
Implementation of lead V8 as a simple non-invasive tool to improve patient selection in cardiac resynchronization therapy (CRT) and guide left ventricular (LV) lead placement
Authors' conclusion
NDAT in lead V8 is a non-invasive marker of delayed activation in the posterolateral LV, outperforming V6 in identifying late activation. When combined with LV-paced QRS morphology, V8 facilitates accurate lead localization without additional tools.
Study context
- Population
- Patients with wide QRS (non-RBBB) undergoing BiV-CRT implantation or generator change
- Participants
- 43 patients
- Exposure
- Negative derivative activation time (NDAT) in ECG lead V8 vs QLV interval
- Outcome
- Correlation of NDAT in lead V8 with the QLV interval
Methodological detailsconsecutive patients
- Consecutive patients
Main finding
As reported in the abstract
Correlation of NDAT with QLV
| Group | R | Mean difference vs QLV |
|---|---|---|
| V8 | 0.895 | 1 ± 11 ms |
| V6 | 0.592 | 21 ± 24 ms |
R
V80.895
V60.592
Mean difference vs QLV
V81 ± 11 ms
V621 ± 24 ms
Observational data: associations, not effects.
Further findings
V8 morphology during LV-only pacing
- QS morphology in V8 consistently indicated posterolateral LV lead placement
- More anterior/apical lead positions showed larger QLV–NDAT V8 differences and non-QS morphologies, indicating suboptimal positioning
Original publication
Implementation of lead V8 as a simple non-invasive tool to improve patient selection in CRT and guide LV lead placement. Europace. Published 29 August 2025. doi:10.
Summarised from the published abstract; every number is checked against it