Arrhythmias & electrophysiologyResearch article
Quantitative CT Lead Localization Reveals Proximal Left Bundle Targeting Facilitates Superior Physiologic Pacing
- proof-of-concept anatomic study
- consecutive patients
- observer-independent computed tomography workflow (CARA workflow)
- prespecified rule
Authors' conclusion
In this proof-of-concept anatomic study, a 2-measurement rule classified CSP lead position objectively. Near-native paced activation requires proximal targeting (LH ≤ 25 mm), which neither the procedural label nor the ECG can identify; quantitative imaging is required.
Study context
- Population
- Consecutive patients undergoing conduction system pacing (CSP) with interpretable computed tomography anatomyof 186 consecutive patients undergoing CSP, with interpretable computed tomography anatomy, primary analysis set n = 46 · proximal 68 · distal 70 · left ventricular septal pacing 7
- Participants
- 145 patients
- Comparison
- proximal vs distal CSP lead position
- proximaln = 24
- distaln = 22reference
- Outcome
- |Δ frontal axis| ≤ 15° and |Δ QRS duration| ≤ 15 ms (composite end point)
Main finding
As reported in the abstract
Each group vs distalOdds ratio (95% CI)P value
proximal
4.14(1.23–13.96)
P = 0.021- proximal
- adjusted odds ratio 5.35; P = 0.013
Further findings
Positional information of procedural label
- physician-labeled left bundle branch pacing leads that were proximal
- 48%
- proximal overall
- 49%
Receiver operating characteristic-optimal LH cut point
- LH cut point
- 24.9 mm
- independently reproduced the prespecified 25-mm threshold
Position classification from surface ECG
- classification area under the curve
- 0.48
Original publication
Quantitative CT Lead Localization Reveals Proximal Left Bundle Targeting Facilitates Superior Physiologic Pacing. Heart Rhythm. Published 20 September 2026. doi:10.1016/j.hrthm.2026.09.012
Summarised from the published abstract; every number is checked against it