Brugada-Syndrom
A cardiac "channelopathy" resulting from mutations in genes coding for cardiac sodium (Na+) channels, the Brugada syndrome is a common cardiac cause of sudden death in patients with structurally normal hearts.
Epidemiology
Age of diagnosis ranges from 2 days to 84 years old. It is estimated to cause 4% of all sudden deaths and in excess of 20% of sudden deaths that occurs in patients without structural cardiac abnormalities. It is the second leading cause of death in males under 40 years old in the countries in which it is endemic (primarily located in Southeast Asia) .
Clinical presentation
Patients may report a medical history of unexplained ventricular tachycardia/fibrillation, or a family history of sudden death under the age of 45. Presenting complaints may include:
- syncope
- paroxysms of nocturnal agonal respirations
- sudden cardiac death
ECG
There are three (types 1-3) typical Brugada patterns, the first of which is the "Brugada sign" and the only pattern which may (with a suggestive history) be diagnostic, with types 2 and 3 only suggestive. Their electrocardiographic features are found in the right sided precordial leads (leads V1-V3) and are as follows:
- type 1
- appearance referred to as the "Brugada sign"
- incomplete/complete right bundle branch block (RBBB) morphology
- rSR' pattern, complete RBBB has a QRS duration > 0.12 seconds, incomplete between 0.10-0.12 seconds
- elevation of the ST segment with a "coved" morphology
- 2 mm elevation or more, 2 leads or more
- inversion of the T wave
- type 2
- incomplete/complete RBBB morphology
- elevation of the ST segment with a "saddleback" morphology
- 2 mm elevation or more, 2 leads or more
- inversion of the T wave
- type 3
- incomplete/complete RBBB morphology
- has either "coved" or "saddleback" ST elevation of >1 mm in 2 or more leads
- incomplete/complete RBBB morphology