LAUSR

BACKGROUND Intraventricular conduction disturbances are associated with an increased risk of adverse cardiovascular outcomes. However, data about factors associated with intraventricular conduction disturbances are sparse. We aimed to identify the clinical factors associated with intraventricular conduction disturbances in the general population. METHODS Cross-sectional study in a sample of 3704 participants (age range 45-86 years, 55.2% women). Intraventricular conduction disturbances were defined as QRS > 110 ms on electrocardiograms, and classified into right bundle branch block (RBBB), left bundle branch block (LBBB), left anterior fascicular block (LAFB) and non-specific intraventricular conduction disturbances (NIVCD). RESULTS The number of participants, the resulting prevalence (square brackets) and 95% CI (round brackets) of intraventricular conduction disturbances and subtypes (RBBB, LBBB, LAFB and NIVCD) were 187 [5.1% (4.4-5.8%)], 103 [2.9%, (2.3-3.4%)], 29 [0.8% (0.6-1.1%)], 31 (0.9% [0.6-1.2%]), and 47 [1.3% (0.9-1.7)], respectively. Multivariable logistic regression identified male sex [odds ratio and (95% CI): 2.55 (1.34-4.86)] and increasing age (p-value for trend <0.001) as being associated with RBBB; hypertension [3.08 (1.20-7.91)] and elevated NT-proBNP [3.26 (1.43-7.41)] as being associated with LBBB; elevated NT-proBNP [3.14 (1.32-7.46)] as being associated with LFAB; and male sex [5.97 (1.91-18.7)] and increased height [1.31 (1.06-1.63)] as being associated with NIVCD. CONCLUSION In a sample of the Swiss middle-aged population, the clinical factors associated with intraventricular conduction disturbances differed according to the intraventricular conduction disturbances subtype: male sex and ageing for RBBB; hypertension and elevated NT-proBNP for LBBB; elevated NT-proBNP for LAFB; and male sex and increased height for NIVCD.