Association between atrial fibrillation and bundle branch block.

Background: The association between atrial fibrillation (Afib) and sinus and AV nodal dysfunction has previously been reported. However, no data are available regarding the association between Afib and bundle branch block (BBB).

Methods: Patient data were obtained from the Nationwide Inpatient Sample (NIS) database between years 2009 and 2015. Patients with a diagnosis of Afib and BBB were identified using validated International Classification of Diseases, 9th revision, and Clinical Modification (ICD-9-CM) codes. Statistical analysis using the chi-square test and multivariate linear regression analysis were performed to determine the association between Afib and BBB.

Results: The total number of patients with BBB was 3,116,204 (1.5%). Patients with BBB had a mean age of 73.5 ± 13.5 years, 53.6% were males, 39.1% belonged to the age group ≥80 years, and 72.9% were Caucasians. The prevalence of Afib was higher in the BBB group, as compared to the non-BBB group (29% vs 11.8%, p value<.001). This association remained significant in multivariate regression analysis with an odds ratio of 1.25 (CI: 1.24-1.25,  < .001). Among the subtypes of BBB, Afib was comparatively more associated with RBBB (1.32, CI 1.31-1.33, p value<.0001) than LBBB (1.17, CI 1.16-1.18, p value<.0001). The mean cost was higher among Afib with BBB, compared with Afib patients without BBB ($15 795 vs $14 391, p value<.0001). There was no significant difference in the mean length of stay (5.6 vs 5.9 days, p value<.0001) or inpatient mortality (4.9% vs 4.8%).

Conclusion: This study demonstrates that prevalence of Afib is higher in patients with BBB than without BBB. Cost are higher for Afib patients with BBB, compared to those without BBB, with no significant increase in mortality or length of stay.