Coronary disease & ACSResearch article
Left septal fascicular block–like electrocardiographic (ECG) pattern in acute coronary syndrome: Clinical presentation and prognostic implications
- Clinical, angiographic, and outcome data were retrospectively analyzed
- consecutive patients
Authors' conclusion
A transient LSFB-like ECG pattern was uncommon but associated with proximal LAD involvement in this ACS cohort. Recognition of this dynamic ECG pattern may help identify septal ischemia and proximal LAD lesions. Further studies are warranted to refine ECG definitions and to clarify the clinical implications of LSFB-like patterns.
Study context
- Population
- Patients with acute coronary syndrome (ACS) treated with emergent percutaneous coronary intervention (PCI) between 2017 and 2024consecutive patients with ACS treated with emergent PCI
- Participants
- 789 patients
Main finding
As reported in the abstract
Transient LSFB-like ECG pattern
Identified in
8 patients (1.0%)
Further findings
Culprit lesion location
- All culprit lesions in the proximal LAD at or proximal to the first septal branch
Ventricular fibrillation before PCI
- Ventricular fibrillation before PCI, of the 8 patients with the pattern
- 3 patients (37.5%)
Recurrence of left septal fascicular block (LSFB)-like pattern on follow-up ECG
- No recurrence observed
Original publication
Left septal fascicular block–like ECG pattern in acute coronary syndrome: Clinical presentation and prognostic implications. Heart Rhythm. Published 23 April 2026. doi:10.1016/j.hrthm.2026.03.1888
Summarised from the published abstract; every number is checked against it