Patients with a family history of Brugada syndrome, tested for the syndrome in childhood, could still test positive later in life, in response to hormonal, autonomic, or genetic factors, according to study published Nov. 16 in the Journal of the American Medical Association. The syndrome, which is characterized by “coved-type ST-segment elevation in the right precordial leads,” can present in infants, but more likely appears in patients 40 to 50 years of age.

Additional Resources Missense Mutations in Plakophilin-2 Cause Sodium Current Deficit and Associate With a Brugada Syndrome Phenotype Adult Congenital and Pediatric Cardiology Member Section

Examining 43 asymptomatic children – who had a family history of Brugada syndrome yet had a negative ajmaline test – Guilio Conte, MD, and his colleagues, investigated the clinical significance of repeating an ajmaline test after puberty.  All of the children had their first test before the age of 16 and continued to have an annual electrocardiogram (ECG) until the onset of puberty (≥ 16 years old), when another ajmaline test was performed.

Results showed that type 1 ECG – the only criterion for diagnosis of Brugada syndrome – was seen in 23 percent of the patients during the ajmaline challenge. Of those patients, three had developed syncope and one, nocturnal agonal respiration prior to the test, at a mean age of 22.5 years. Patients who were symptomatic prior to the ajmaline test were more likely to have a positive repeat test than those who were asymptomatic (75 percent vs. 18 percent, respectively). Genetic testing also revealed that five patients who had tested positive for the syndrome also had a SCN5A mutation.

The authors note that this is the first report of a change in patients in response to ajmaline between childhood and puberty. They indicate in the study that “these findings support the need for repeat monitoring of family members of patients with Brugada syndrome, including those initially considered low risk because of young age.” As the diagnostic type 1 ECG can occur spontaneously, the results of the study suggest that patients with family history of the syndrome should investigate any developing symptoms.

Keywords: Mutation, Brugada Syndrome, Adolescent, Follow-Up Studies, Ajmaline, American Medical Association, Puberty, Heart Conduction System, Syncope, Electrocardiography, Genetic Testing

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