Ajmaline challenge in young individuals with suspected Brugada syndrome

Background: The clinical characteristics and the results of ajmaline challenge in young individuals with suspected Brugada syndrome (BS) have not been systematically investigated.

Methods: Among a larger series of patients included in the BS database of our Department, 179 patients undergoing ajmaline challenge were included in the study and categorized in two groups according to age: group 1 (<18 years old) and group 2 (≥18 years old). Clinical features and results of the ajmaline challenge of each group were compared.

Results: Young individuals were more often asymptomatic compared to adult patients (P = 0.002). They showed a higher number of normal ECGs (P = 0.023), a lower percentage of Brugada type II electrocardiographic pattern compared to the adult population (P = 0.011), and a comparable amount of spontaneous Brugada type III electrocardiographic pattern (P = 0.695). Ajmaline provoked a higher degree of intraventricular conduction delay (P = 0.002) and higher degree of prolongation of the ventricular repolarization phase (P = 0.013) in young individuals but its pro-arrhythmic risk was comparable in the two groups (P = 0.684). Furthermore, inducibility of ventricular arrhythmias in young patients with a positive ajmaline test was comparable to that of the adults with a positive ajmaline test (P = 0.694).

Conclusions: The present study demonstrates the low-risk profile of the ajmaline test in young patients when performed by experienced physicians and nurses in an appropriate environment.