Cardiology MCQ 53: Brugada syndrome

Q. Which of the following is true about Brugada syndrome?

A. AR inheritance

B. Exertional syncope

C. Functional phase 2 re-entry

D. Female preponderance

Answer: C. Functional phase 2 re-entry

Explanation:

Brugada syndrome:

Cause of ventricular arrhythmia in structurally normal heart.

Autosomal dominant genetic disorder.

Loss of function genetic mutation in cardiac sodium channels (SCN5A and SCN10A).

Functional phase 2 re-entry leads to ventricular arrhythmias in Brugada.

ECG: Right bundle branch pattern with ST elevation in V1 to V3 leads.

Types of Brugada syndrome (Image 1):

Type 1: Coved type ST elevation (>/=2 mm) with inverted T waves

Type 2: Saddle-back ST-T wave configuration with an upright or biphasic T wave

                                    Image 1: Types of Brugada syndrome 

Brugada pattern ECG is more common in men as compared to women.

Arrhythmic events more common during night and during sleep (Not during exertion).

Fever and sodium channel blocker (Flecainide, ajmaline, procainamide) can provoke arrhythmias.

These drugs are also used for drug challenge test for diagnosis of Brugada as they unmask the Brugada pattern of ECG.