Clinical differences between drug-induced type 1 Brugada pattern and syndrome.

Area of Science:

• Cardiology
• Electrophysiology
• Genetics

Background:

• Brugada syndrome (BrS) diagnosis often relies on inducing a Type 1 Brugada pattern with sodium channel blockers.
• Limited data exists on the outcomes of diverse patient groups exhibiting drug-induced Type 1 Brugada patterns.
• This study investigates the characteristics and outcomes of individuals with ajmaline-induced Type 1 Brugada patterns.

Purpose of the Study:

• To characterize patients with ajmaline-induced Type 1 Brugada patterns.
• To compare outcomes between patients meeting diagnostic criteria for drug-induced BrS (DIBrS) and those with only the pattern (DIBrECG).
• To assess the long-term prognosis of patients with ajmaline-induced Type 1 Brugada ECG.

Main Methods:

• A multicenter retrospective study was conducted.
• Included consecutive cases of ajmaline-induced Type 1 Brugada pattern from seven centers.
• Patients were categorized into DIBrS and DIBrECG groups for comparison.

Main Results:

• 260 patients (mean age 43.4 years, 69.9% males) were analyzed.
• Syncope, family history of BrS or sudden cardiac death were noted in 21.5%, 22.3%, and 18.1% of patients, respectively.
• Females were overrepresented in the DIBrS group (40% vs. 21.5%). A higher prevalence of type 2/3 Brugada ECG at baseline was observed in the DIBrECG group (80.8% vs. 60%).

Conclusions:

• Less than half of patients with ajmaline-induced Type 1 Brugada patterns met current diagnostic criteria for BrS.
• These individuals experienced a very low rate of adverse outcomes during a 3-year follow-up.
• Prognosis appears favorable regardless of meeting diagnostic criteria or the reason for the ajmaline challenge.