Prevalence, Clinical Characteristics and Management of Atrial Fibrillation in Patients With Brugada Syndrome
Study Questions:
How often is the diagnosis of Brugada syndrome (BrS) preceded by clinically manifest atrial fibrillation (AF)?
Methods:
A BrS database that included 611 patients was reviewed to identify patients with a documented episode of AF prior to the diagnosis of BrS.
Results:
Thirty-five patients (mean age 49 years) had a history of AF before the diagnosis of BrS. A BrS pattern on the electrocardiogram (ECG) became apparent after initiation of treatment with a class I antiarrhythmic agent in 11 patients and during general anesthesia in one patient. Among the remaining 23 patients, a BrS pattern was brought out by an ajmaline challenge performed as part of the diagnostic evaluation in 13 patients with lone AF, five patients with a family history of sudden death, three patients with syncope or aborted sudden death, and two patients with an abnormal ECG. The baseline ECG was normal in 21/35 patients (60%). Electrophysiologic testing disclosed sinus node dysfunction in six patients, right atrial flutter in four, a His-ventricular interval ≥60 ms in five, 1º atrioventricular (AV) block in two, AV reentrant tachycardia in one, and AV nodal reentrant tachycardia in one.
Conclusions:
AF can be the first clinical manifestation of BrS. If BrS is unrecognized, treatment with a class Ic antiarrhythmic drug such as flecainide potentially could result in dangerous ventricular arrhythmias.
Perspective:
The prevalence of AF in the BrS has been estimated to be approximately 20%. The high prevalence of AF suggests that the sodium channel mutation that affects ventricular myocytes in BrS also affects atrial myocytes.
Clinical Topics: Arrhythmias and Clinical EP, Cardiovascular Care Team, Dyslipidemia, Heart Failure and Cardiomyopathies, Implantable Devices, EP Basic Science, Genetic Arrhythmic Conditions, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Lipid Metabolism
Keywords: Brugada Syndrome, Heart Atria, Sick Sinus Syndrome, Baroreflex, Syncope, Electrophysiologic Techniques, Cardiac, Electrocardiography, Heart Rate, Sodium Channels, Tachycardia, Mutation, Prevalence, Atrioventricular Block, Death, Muscle Cells, Flecainide, Atrial Flutter
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