Role of Provocable Brugada ECG Pattern in The Correct Risk Stratification for Major Arrhythmic Events.

Area of Science:

• Cardiology
• Electrophysiology
• Sudden Cardiac Death Research

Background:

• Brugada syndrome (BS) presents a distinct ECG pattern resembling right bundle branch block with ST segment elevation.
• BS is linked to conduction delays, potentially due to right ventricular outflow tract fibrosis, and carries a risk of sudden cardiac death.
• The ajmaline challenge test is used to unmask latent conduction defects in BS but its diagnostic utility is debated due to variable specificity and sensitivity.

Purpose of the Study:

• To evaluate the effectiveness of the ajmaline challenge test in risk stratification for asymptomatic individuals with a non-diagnostic Brugada ECG pattern.
• To determine if a positive ajmaline test provides additional information beyond baseline ECG for identifying individuals at risk of major ventricular arrhythmic events.

Main Methods:

• Review of evidence-based studies on ajmaline challenge test in Brugada syndrome.
• Analysis of the impact of ajmaline-induced Type 1 ECG patterns in various cardiac and systemic diseases.
• Assessment of the ajmaline test's role in risk stratification for asymptomatic individuals with non-diagnostic BS ECGs.

Main Results:

• The Type 1 Brugada ECG pattern can be induced by ajmaline in conditions other than BS, including LQTS, ARVC, HCM, and myotonic dystrophy, without a clear associated arrhythmic risk.
• Evidence-based studies indicate that a positive ajmaline test does not enhance risk stratification for major ventricular arrhythmic events in asymptomatic individuals with a non-diagnostic Brugada ECG pattern.

Conclusions:

• The ajmaline challenge test is not a reliable tool for risk stratification in asymptomatic individuals with non-diagnostic Brugada syndrome ECGs.
• The induction of a Type 1 ECG pattern by ajmaline in other cardiac conditions highlights its lack of specificity for Brugada syndrome.
• Further research may be needed to identify more specific and sensitive markers for sudden cardiac death risk in Brugada syndrome.