Left Ventricular Ejection Fraction and Incident Cardiac Conduction Dysfunction: Exploring the Mediating Effects of...

Area of Science:

• Cardiology
• Electrophysiology
• Biomedical Engineering

Background:

• Population-based data on left ventricular ejection fraction (LVEF) predicting cardiac conduction dysfunction (CCD) and electrophysiological mediation is limited.
• Understanding the relationship between LVEF and incident CCD is crucial for cardiovascular health.
• This study investigates the predictive role of LVEF and potential mediation by electrophysiological parameters in a large cohort.

Purpose of the Study:

• To determine if LVEF predicts incident CCD in a large population.
• To explore the mediating roles of PQ interval, QRS duration, and corrected QT interval in the LVEF-CCD relationship.
• To elucidate the clinical relevance of myocardial mechano-electrical coupling.

Main Methods:

• Prospective cohort study of 32,398 UK Biobank participants with LVEF and ECG data.
• Incident CCD defined as new onset atrioventricular block, left bundle branch block, or other conduction disorders.
• Cox regression, sensitivity analyses, and mediation analysis (PQ, QRS, QT intervals) were employed.

Main Results:

• A total of 484 incident CCD cases were identified during ~7 years of follow-up.
• Each 1-SD increase in LVEF was associated with a 17% reduced risk of CCD (aHR=0.83, p<0.001).
• PQ interval, QRS duration, and corrected QT interval mediated 6%, 17%, and -3% of the LVEF-CCD association, respectively.

Conclusions:

• LVEF is an independent predictor of incident CCD.
• Electrophysiological parameters partially mediate the association between LVEF and CCD.
• Findings emphasize the clinical significance of myocardial mechano-electrical coupling in population health.