Arrhythmias & electrophysiologyDiagnostic or prognostic study
A Revised Definition of Left Bundle Branch Block Using Time to Notch in Lead I
- Diagnostic accuracy study
- single-centre
- prospective derivation cohort
- retrospective validation cohort
Authors' conclusion
The findings suggest that time to notch longer than 75 milliseconds in lead I is a simple ECG criterion that, when used in conjunction with standard LBBB criteria, may improve specificity for identifying patients with LBBB from conduction block.
Study context
- Population
- Patients with baseline left bundle branch block (LBBB) on 12-lead electrocardiography (ECG) undergoing electrophysiological study (derivation); patients with new LBBB after transcatheter aortic valve replacement (TAVR) (validation)validation cohort n = 46
- Participants
- 75 patients
- Comparison
- Time to notch >75 ms in lead I vs Strauss criteria
- Outcome
- Sensitivity and specificity of ECG criteria in patients with LBBB or IVCD (by intracardiac recording)
Performance
As reported in the abstract
Diagnostic performance, derivation cohort
| Test or model | sensitivity | specificity |
|---|---|---|
| Time-to-notch criterion | 71% (95% CI, 56%-83%) | 74% (95% CI, 54%-89%) |
| Strauss criteria | 96% (95% CI, 86%-99%) | 33% (95% CI, 17%-54%) |
Further findings
| Outcome | Values | P value |
|---|---|---|
| Notch or slur in lead I, CCB vs IPA (derivation) | CCB 83.3% · IPA 48.1% | P = 0.003 |
| Diagnostic performance, TAVR validation cohort | Time-to-notch criterion sensitivity 87% (95% CI, 74%-95%) |
- Notch or slur in lead I, complete conduction block (CCB) vs intact Purkinje activation (IPA) (derivation): CCB n = 48; IPA n = 27
Diagnostic performance, TAVR validation cohort
- Criterion correctly distinguished intraventricular conduction delay (IVCD) from LBBB in all 10 patients with preprocedural IVCD
- Strauss criteria performed similarly in the validation cohort
Original publication
A Revised Definition of Left Bundle Branch Block Using Time to Notch in Lead I. JAMA Cardiol. Published 1 May 2024. doi:10.1001/jamacardio.2024.0265
Summarised from the published abstract; every number is checked against it