The Definition of the Brugada Syndrome
- Sieira J, Brugada P.
- The Definition of the Brugada Syndrome. Eur Heart J 2017;Aug 31:[Epub ahead of print].
The following are key points to remember from this review of the diagnostic criteria for the Brugada syndrome (BS):
- In the initial reports of BS, three types of ST segments were described: type 1—coved ST segments with ST-segment elevation >2 mm, followed by a negative T-wave; type 2—J point elevation ≥2 mm with gradual ST-segment descent followed by a positive or biphasic T-wave (saddle back configuration); and type 3—ST-segment elevation <1 mm, either coved or saddle back, in leads V1-V3.
- The contemporary definition of BS is the type 1 pattern in ≥1 right precordial lead.
- The type 1 pattern can be recorded with V1 and/or V2 positioned in the second, third, or fourth intercostal space.
- The type 1 pattern is diagnostic of BS whether occurring spontaneously or with an intravenous drug challenge using a class I antiarrhythmic drug.
- A type 2 pattern raises the suspicion of BS, but the diagnosis depends on the emergence of a type 1 pattern with a drug challenge.
- The type 3 pattern no longer is thought to have any significance in diagnosing BS.
- In the past, a type 1 pattern was necessary in >1 right precordial lead, but in the contemporary definition, a type 1 pattern in a single right precordial lead (V1 or V2) is sufficient.
- Lead V3 is no longer thought to have incremental diagnostic value compared with leads V1 and V2.
- A right bundle branch block can mimic BS, but differs in that the ST-segment is not elevated in leads V1-V2 and the QRS is wider than in BS.
- If the diagnosis is not clear-cut, vectorcardiography can help differentiate BS from other conditions such as early repolarization or right bundle branch block.
Keywords: Anti-Arrhythmia Agents, Arrhythmias, Cardiac, Brugada Syndrome, Bundle-Branch Block, Heart Conduction System, Vectorcardiography
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