Functional Bowel Disorders in Patients with Brugada Syndrome and
Drug-Induced Type 1 Brugada Pattern
Abstract
Introduction: Irritable bowel syndrome (IBS) is one of the most widely
recognized functional bowel disorders (FBDs) with a genetic component.
SCN5A gene and SCN1B loci have been identified in population-based IBS
cohorts and proposed to have a mechanistic role in the pathophysiology
of IBS. These same genes have been associated with Brugada syndrome
(BrS). The present study examines the hypothesis that these two
inherited syndromes are linked. Methods and Results: Prevalence of FBDs
over a 12 months period were compared between probands with
BrS/drug-induced type 1 Brugada pattern (DI-Type1 BrP) (n=148) and a
control group (n=124) matched for age, female sex, presence of
arrhythmia and co-morbid conditions. SCN5A/SCN1B genes were screened in
88 patients. Prevalence of IBS was 25% in patients with BrS/DI-Type1
BrP and 8.1% in the control group (p=2.34×10−4). On stepwise logistic
regression analysis, presence of current and/or history of migraine (OR
of 2.75; 95% CI: 1.08 to 6.98; p=0.033) was a predictor of underlying
BrS/DI-Type1 BrP among patients with FBDs. We identified 8 putative
SCN5A/SCN1B variants in 7 (12.3%) patients with BrS/DI-Type1 BrP and 1
(3.2%) patient in control group. Five out of 8 (62.5%) patients with
SCN5A/SCN1B variants had FBDs. Conclusion: IBS is a common co-morbidity
in patients with BrS/DI-Type1 BrP. Presence of current and/or history of
migraine is a predictor of underlying BrS/DI-Type1 BrP among patients
with FBDs. Frequent co-existence of IBS and BrS/DI-Type1 BrP
necessitates cautious use of certain drugs among the therapeutic options
for IBS that are known to exacerbate the Brugada phenotype.