Arrhythmias & electrophysiology
New ECG Morphologic Criteria for the Identification of Left Bundle Branch Capture
Authors' conclusion
Simple electrocardiogram morphologic criteria can accurately identify LBBc during left bundle branch area pacing in patients with baseline narrow QRS and/or without cardiomyopathy.
Study context
- Population
- Patients with proven LBBc based on the presence of QRS transition during decremental output pacing during left bundle branch area pacingpatients with proven LBBc
- Participants
- 115 patients
- Comparison
- ECG morphologic criteria for the identification of LBBc
- Outcome
- Mean V6 QRS upstroke duration
Performance
As reported in the abstract
P < 0.001
Further findings
Identification of correct capture pattern by independent evaluators using exclusively qualitative criteria · significantly lower among dilated cardiomyopathy patients
diagnostic accuracy 70.4% vs 93% · P = 0.004
Paced V6 upstroke/downstroke ratio <1 for identification of LBBc
- Sensitivity
- 0.97
- Specificity
- 0.95
Slurred/notched QRS downstroke or "M" pattern in inferior leads, in baseline narrow QRS patients with inferior paced QRS axis
- Present during LBBc
- 91.1%
- Sensitivity
- 0.91
- Specificity
- 0.87
Original publication
New ECG Morphologic Criteria for the Identification of Left Bundle Branch Capture. JACC Clin Electrophysiol. Published 25 June 2025. doi:10.
Summarised from the published abstract; every number is checked against it