Wide Complex Tachycardia and Flecainide: A Dangerous Couple

Area of Science:

• Cardiology
• Electrophysiology
• Medical Diagnostics

Background:

• Wide complex tachycardia (WCT) diagnosis in patients on anti-arrhythmic drugs presents challenges.
• Conventional electrocardiogram (ECG) criteria for WCT can lack specificity.
• Caution is advised when applying standard diagnostic criteria in this patient population.

Purpose of the Study:

• To highlight the diagnostic difficulties in differentiating WCT in patients using anti-arrhythmic medications.
• To emphasize the need for careful interpretation of ECG findings in this context.
• To propose a specific screening recommendation for Brugada Syndrome.

Main Methods:

• Review of clinical cases and diagnostic challenges associated with WCT.
• Analysis of the specificity of conventional ECG criteria in patients on anti-arrhythmic therapy.
• Correlation of flecainide-induced arrhythmias with underlying cardiac conditions.

Main Results:

• Conventional ECG criteria for WCT are often poorly specific in patients taking anti-arrhythmic drugs.
• Life-threatening arrhythmias post-flecainide infusion warrant further investigation.
• Concomitant sinus node dysfunction increases the suspicion for Brugada Syndrome.

Conclusions:

• Differential diagnosis of WCT in patients on anti-arrhythmics requires careful consideration beyond standard ECG criteria.
• Patients experiencing arrhythmias after flecainide should be evaluated for Brugada Syndrome.
• The presence of sinus node dysfunction alongside flecainide-induced arrhythmias is a key indicator for Brugada Syndrome screening.