Neurally mediated susceptibility in individuals with Brugada-type ECG pattern

Area of Science:

• Cardiology
• Autonomic Nervous System Research
• Clinical Electrophysiology

Background:

• Neurally mediated syncope and Brugada syndrome (BS) share autonomic nervous system modulation mechanisms, particularly increased vagal tone.
• Investigating neurally mediated susceptibility in individuals with Brugada-type electrocardiogram (ECG) patterns is crucial for understanding shared pathophysiology.

Purpose of the Study:

• To determine the incidence of neurally mediated syncope susceptibility in individuals with a Brugada-type ECG pattern.
• To explore the relationship between autonomic dysfunction and Brugada syndrome.

Main Methods:

• Eight asymptomatic males with Brugada-type ECG patterns and 25 healthy controls underwent drug-free head-up tilt testing.
• Participants had structurally normal hearts and normal ECGs (controls).

Main Results:

• A positive tilt test response was observed in 37% of subjects with Brugada-type ECG patterns (3/8).
• In comparison, 12% of healthy controls (3/25) had a positive tilt test response (P = 0.018).

Conclusions:

• Asymptomatic individuals with Brugada-type ECG patterns exhibit a high incidence of neurally mediated syncope susceptibility.
• The coexistence of these conditions presents diagnostic and therapeutic challenges, potentially misleading risk stratification.
• Further research is needed to validate these findings and assess the tilt test's role in managing Brugada syndrome patients.