Are there sex differences in patients with syncope and bundle branch block?

Abstract

Abstract Background In the last years a substantial effort has been made to improve the understanding of the sex-differences in cardiovascular disease. However, no studies have examined differences in presentation and outcomes between men and women presenting with syncope and bundle branch block (BBB). Aim To determinate if there are sex-specific differences in the characteristics and outcomes of syncope in patients with BBB Methods Cohort study carried out in a tertiary hospital that is a reference center for syncope from January 2008 to February 2021. Patients (p.) with BBB and syncope of unknown origin after the initial evaluation without direct indication of an ICD were included. They were managed according to the current ESC guidelines. All patients underwent to an EPS and an ILR was implanted if it was not diagnostic. Results 374p. were included (75±1 y. o; 135 (36%) female). Mean follow up was 2.3±1.6 y.o. No differences in baseline characteristics where found comparing both groups, except that LBBB was more prevalent in female and RBBB in male (Figure 1A). EPS and ILR diagnostic yield was 44%/44% respectively in females and 50% /40% in males (p=ns). However, basal HV interval in EPS was significant shorter in females (Figure 2A). In the multivariate analyses female sex was associated with a significant lower risk of AV block (Figure 1B), and with a trend of less need of a pacemaker implantation (PM) (53% in females, 60% in males) (Log-rank 0.1) (Figure 2B). No significant differences in recurrences neither in mortality rate were found. Conclusions Female patients with syncope and BBB have lower risk of AV block compared to males, and only half of them required a pacemaker implantation. A strategy of direct PM implantation should be avoided, specially in woman. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2