Arrhythmias & electrophysiologyResearch article
Prognostic implications of intraventricular conduction disorders for the risk of sudden cardiac death in cardiac patients
- analysis of data from 4 cohorts
- Intraventricular conduction disorders (IVCDs) classified by researchers blinded to outcome data
- subdistribution hazard (SDH) analysis
Authors' conclusion
NIVCD and prolonged QRS are strong predictors of SCD events despite adjusting for risk factors including LVEF.
Study context
- Population
- Cardiac patients undergoing either coronary angiography or clinical exercise testingcardiac patients in 4 cohorts, 1162 sudden cardiac death (SCD) events
- Participants
- 26,028 patients
- Comparison
- The risk associated with IVCDs compared with normal QRS
Main finding
As reported in the abstract
Share of SCDs occurring in patients with IVCD · median follow-up 8.4 years (5.5-11.6)
Patients with IVCD (19.2% of all patients; n = 5007) accounted for share of all SCDs
33% (30%-36%)
SCD events
1162
Further findings
| Outcome | SDH (95% CI) | P value |
|---|---|---|
| SCD — NIVCD vs normal QRS · age- and sex-adjusted · age- and sex-adjusted analysis | 2.7 (2.1–3.6) | P < 0.0001 |
| SCD — LBBB vs normal QRS · age- and sex-adjusted · age- and sex-adjusted analysis | 2.0 (1.5–2.6) | P < 0.0001 |
| SCD — prolonged QRS vs normal QRS · age- and sex-adjusted · age- and sex-adjusted analysis | 1.9 (1.6–2.3) | P < 0.0001 |
| SCD — right bundle branch block vs normal QRS · age- and sex-adjusted · age- and sex-adjusted analysis | 1.5 (1.1–1.9) | P = 0.003 |
SCD, adjusted for baseline clinical risk factors and left ventricular ejection fraction (LVEF)
- Nonspecific IVCD (NIVCD) and prolonged QRS also associated significantly with SCD despite adjusting for baseline clinical risk factors and LVEF
- Left bundle branch block (LBBB) associated significantly with SCD after adjusting for risk factors but not after adjusting for LVEF
Original publication
Prognostic implications of intraventricular conduction disorders for the risk of sudden cardiac death in cardiac patients. Heart Rhythm. Published 23 March 2026. doi:10.1016/j.hrthm.2026.03.1912
Summarised from the published abstract; every number is checked against it