Brugada syndromeThe Study case presented in #ECGclass Case 26 is typical of Brugada syndrome. It is quite likely that this man's father died of undiagnosed Brugada syndrome in his sleep.
Brugada syndrome is an inherited channelopathy that results from a sodium ion channel abnormality.
Its presents in the 20-50yrs age group, with a prevalence of around 1 in 2000, and is more common in men (8-10 times), especially South Asian men.
Can cause sudden cardiac death due to fast polymorphic Ventricular Tachycardia - usually during rest/sleep overnight.
Mean age of sudden death is 41yrs (+/- 15yrs)
Brugada accounts for 4% of all Sudden Cardiac Deaths (and >20% of sudden cardiac deaths in structurally normal hearts)
For every 10 patients who present with syncope as a result of Brugada syndrome, 8 of them will be diagnosed only after cardiac arrest.
- May be an asymptomatic, incidental ECG finding
- Syncope? (check family history)
- Symptoms triggered by medication or alcohol? (see below)
- Sudden Cardiac Death.
ECG changesThe classical ECG changes of Type I Brugada are: ST elevation in V1-V3 and partial RBBB. These ECG changes may be dynamic or 'concealed'.
Greater than 2mm ST elevation in V1-3 correlates, with increased arryhtmia risk and ICD is the definitive treatment.
If concealed, the ECG changes can sometimes be revealed by a Flecainaide or Ajmaline challenge. (Helpful to aid diagnosis)
Some lifestyles and medication can allow Brugada to manifest itself:
- Drugs - Sodium channel blockers, Beta-blockers, Tricyclics
- Toxicity - typically alcohol or cocaine
So for patients who present with symptoms suggestive of arrhythmia, which are triggered by any of the above, don't forget to think about Brugada.
ECG changes of Brugada, can be subdivied into 2 types, but management is the same i.e. consider ICD in high risk individuals.
Type I Brugada - ECG changes:
(Coved ST elevation in V1-3, with negative T waves)
Type 2 Brugada - ECG changes:
(Saddleback ST elevation in V1-3 with the trough still >1mm elevated. High take off >2mm. T waves may be +ve or -ve)
|(Images, inc. #ECGclass case 26, thank you to ECGpedia.org)|
The spectrum of clinical presentation and prognosis in Brugada syndrome can vary enormously.
At one end patients may have normal prognosis/no symptoms; through asymptomatic and ECG abnormalities/risks only if exposed to harmful drug triggers; to syncopal episodes/High risk and spontaneously abnormal ECG/spontaneous VF without triggers - certain death.
Greater than 2mm ST elevation in V1-V3 correlates with an increased risk of ventricular arrhythmia.
- Less than 1% risk if no symptoms, no family history and no spontaneous ECG changes
- 30% risk if syncope or cardiac arrest ( FINGr registry outcome data - see below)
So, we now know that our patient in #ECGclass Case 26 is at high risk (Syncope + Type 1 ECG changes + suggestive Family history)
- ICD - depending on individual risk assessment and patient choice. (Recommended in patients with symptoms, and Type I ECG)
- Genetic screening/12lead ECG/Ajmaline testing - should be offered to family members.
- Check risk stratification data with FINGr registry (France/Italy/Netherlands/Germany registry)
- Rare and unusual - but think about it!
- Always consider a possible malignant arrhythmia in unexplained syncope.
- Check family history of sudden death (eg. In sleep? Unexplained drowning? Seizures? etc - they won't necessarily know that they have a family history of 'cardiac arrhythmia'!)
- May be seen only intermittently on ECG
- Think Brugada in an ECG with complete (or incomplete) RBBB and persistent ST elevation in V1-V3. (Sometimes Brugada is misdiagnosed as an acute MI).