Arrhythmic Events in Young Patients With Brugada Syndrome

Apr 09, 2019
Font Size
A
A
A
Authors:
Michowitz Y, Milman A, Andorin A, et al.
Citation:
Characterization and Management of Arrhythmic Events in Young Patients With Brugada Syndrome. J Am Coll Cardiol 2019;73:1756-1765.
Summary By:
Eugene H. Chung, MD, MPH, FACC

Study Questions:

What are the clinical, electrophysiological, and genetic characteristics of young Brugada syndrome (BrS) patients with arrhythmic events (AEs), and what are the effects of current management strategies once an AE has occurred?

Methods:

This study was an extension of the SABRUS (Survey on Arrhythmic Events in Brugada Syndrome) study. Fifty-seven young patients from 24 different centers formed the study cohort. Inclusion criteria were age ≤20 years old, either a spontaneous or drug-induced type I Brugada electrocardiogram (ECG), and a documented episode of a first sustained ventricular tachyarrhythmia (AE). Acquired data included history of syncope, presence of SCN5A mutation, fever at time of AE, history of sinus node dysfunction (SND), and results of electrophysiology study (EPS). ECG parameters such as QRS fragmentation and S wave in lead I were recorded. Management after the first AE and details of any second AE were documented. The cohort was divided into pediatric (≤12 years old) and adolescent (≥13 and ≤20 years old) groups.

Results:

For the full cohort, the median age at first AE was 14 years old; 73.7% were male, 70.2% Caucasian, 78.9% probands (first patient with diagnosis in family). The AE was aborted cardiac arrest in 84.2% and associated with fever in 28.1%. EPS protocols were variable among centers, but 56.1% did undergo ventricular stimulation with 28.1% of these positive for induced ventricular fibrillation. Of the 75.4% who underwent genetic testing, 58.1% had an SCN5A mutation. When comparing the pediatric (n = 26) and adolescent (n = 31) groups, the pediatric patients were significantly more likely to be female and Caucasian. Pediatric patients were also more likely to have a spontaneous type I Brugada ECG pattern and fever around the time of the first AE.

AE management and follow-up were available for 50 (22 pediatric, 28 adolescent) of the 57 patients. (Of note, data for seven patients were not available due to death from adverse events related to the AE.) For both pediatric and adolescent patients, the incidence of a second AE was similar and high (68.1% and 64.3% respectively). Median time to recurrence was 9.9 (pediatric) and 27.2 months (adolescent). Pediatric patients with fever at the time of first AE were significantly likely to have fever at the second AE; this association was not seen in the adolescent group. Five adolescent patients underwent catheter ablation after the second AE with no AE recurrences post-procedure.

Predictors of AE recurrence in the pediatric group were SND, atrial arrhythmias, intraventricular conduction delay (IVCD), and large S wave in lead I; in adolescent patients, presence of SCN5A mutation predicted AE recurrence.

Conclusions:

Young BrS patients with an AE have a high recurrence rate with a relatively short median time to recurrence. Clinical characteristics differ between pediatric and adolescent patients. Fever is associated with recurrent AE, particularly in the youngest patients. Therapies beyond the implantable cardioverter-defibrillator must be considered in the management of these patients.

Perspective:

This retrospective, observational, multicenter cohort study is the largest to date in young symptomatic patients with BrS. Some points of emphasis:

  1. In the pediatric group (≤12 years old), there was a higher proportion of girls, higher rate of fever-associated first AE, and a high rate of fever-associated second AE.
  2. SCN5A mutations were found at a high rate in the overall cohort, much higher than expected in the general population (adults) with BrS. The mechanism(s) for this association requires further study, especially in adolescent age patients.
  3. SND, atrial arrhythmias, IVCD, and large S wave in lead I can identify pediatric patients at the highest risk of recurrence. The association of the S wave in lead I has been examined previously in adult BrS patients.
  4. Approximately 33% of recurrent AEs occurred despite quinidine, but this study was not designed to assess this therapy. As the authors suggest, there may be a role for concomitant beta-blockade. Endocardial and/or epicardial catheter ablation is an evolving option in select cases and at specialized centers.
  5. Most importantly, in pediatric BrS patients with a prior fever-associated AE, fever should be aggressively managed; based on the authors’ findings, treating fever as a medical emergency is warranted.

Keywords: Arrhythmias, Cardiac, Atrial Fibrillation, Brugada Syndrome, Catheter Ablation, Defibrillators, Implantable, Electrocardiography, Electrophysiology, Genetic Testing, Heart Arrest, Mutation, Pediatrics, Quinidine, Sick Sinus Syndrome, Syncope, Tachycardia, Ventricular, Ventricular Fibrillation


< Back to Listings