|
 |
| HISTORY OF MEDICINE |
|
| Year : 2020 | Volume
: 21
| Issue : 2 | Page : 123-124 |
|
|
Evolution of brugada syndrome
Rachel Hajar M.D., F.A.C.C
Department of Cardiology, Heart Hospital, Hamad Medical Corporation, Doha, Qatar
| Date of Submission | 01-Mar-2020 |
| Date of Acceptance | 01-Mar-2020 |
| Date of Web Publication | 29-Jun-2020 |
Correspondence Address:
Dr. Rachel Hajar
Sr. Consultant Cardiologist, Director of HH Publications and Executive Coordinator for Research; Director of Non-Invasive Cardiology (1981–2014), Heart Hospital, Hamad Medical Corporation, Doha
Qatar
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/HEARTVIEWS.HEARTVIEWS_29_20
How to cite this article:
Hajar R. Evolution of brugada syndrome. Heart Views 2020;21:123-4 |
 Milestones in Our Understanding of Brugada Syndrome | |  |
1953 – Osher and Woff noticed the right bundle branch block (RBBB) with associated ST segment elevation in the right precordial lead on electrocardiogram (ECG) and considered as normal variant and having no relation to sudden cardiac death (SCD).[1]
1975 – Calo[2] reported an ECG triad: R' wave, SR segment elevation, and negative T wave in the right percordial leads. It was still considered a normal variant.
1980s – Center for Disease Control in Atlanta, USA, observed an abnormally high incidence of SCD in Asian refugees who immigrated to the USA from Thailand and were known in the country as “Lai Tai (death during sleep).”[3]
1986 – Prof. Pedro Brugada receives his first patient with typical ECG features of Brugada – a Polish Caucasian child, who suffered several episodes of syncope with a sister who died of SCD.[4]
1989 – In 1989, a patient with the characteristic ECG was described as being a carrier of early repolarization syndrome.[5]
1991 – Brugada and Brugada presented an abstract in the NASPE meeting of a new clinical-cardiologic syndrome, characterized by the association of RBBB, persistent ST segment elevation, normal QT interval, and SCD.[6]
1992 – The Brugada brothers presented the first description of the entity in the J Am Coll Cardiol.[6]
1993–1995 – Several investigators describe the syndrome identified by the Brugada brothers with some critiquing the entity. The Brugada brothers responded in an Italian publication that the new entity they described has no underlying structural heart disease.[7]
1996 – Two authors said in an article on studying the cellular basis of J wave in ECG that they used the eponym Brugada for the first time to describe the syndrome discovered 4 years earlier.[8] Ikeda et al. also called the typical ECG signs of the new entity as “Brugada type.”[9] Subsequently, several authors used the term “Brugada” when referring to the syndrome.
1998 – Identification of the genetic mutations in Brugada disease was identified and finally accepted as an entity. Chen identified three mutations in the SNC5A of chromosome 3p21–p24 which are responsible for Brugada disease.
1999 – Blazer included Brugada disease within the chapter of ion channel diseases or channelopathies. He showed that the affected channels in Brugada disease are primarily the fast sodium (Na) channel and secondarily the initial potassium outflow channel. Bessina et al. identified a single mutation in the Na channel, which was responsible for both Brugada disease and congenital long QT syndrome, that is, they share the same locus.
2000 – Noninvasive markers of value in the risk stratification of Brugada disease - Only high-resolution ECG has value in identifying a patient at high risk. High-resolution ECG has a sensitivity of 89%, a specificity of 50%, a positive predictive value of 70%, and a negative predictive value of 77% for the presence of late potentials.[9] In a prospective study of 52 families, Priori et al.[10] made the following conclusions:
- Asymptomatic individuals with Brugada-type ECG pattern present a very low risk of SCD
- Symptomatic individuals with aborted SCD present 23% of the rate in a mean 33-month follow-up
- The genetic mutation can be identified in 15% of the cases
- The positive electrophysiologic study has a 50% of accuracy
- Pharmacological tests have only a 35% of accuracy in asymptomatic carriers.
2001 – Major and minor criteria for diagnosing this entity were made.[11] The authors proposed that the presence of a major criterion and a minor criterion one constitutes a diagnosis. Major criteria: ECG pattern in a patient without structural heart disease and a positive pharmacological test. Minor criteria: The presence of positive family history, syncope of unknown origin, documented episode of ventricular tachycardia/ventricular fibrillation (VF), and inducibility in the electrophysiologic and positive genetic study.
2002 – Genetic studies[12] showed that unexplained nocturnal SCD syndrome, known as sudden unexplained nocturnal death syndrome, and Brugada disease are phenotypically, genetically, and functionally identical and allelic since both affect the same gene: SCN5A.
2003 – Atarashi et al.[13] suggested that new ECG criteria would indicate high risk of VF in Brugada. Thus, the authors established the following:
- S wave of duration ≥80 ms in V1 has a predictive value of 40.5% and a negative predictive value of 100% for VF with a 100% sensitivity
- ST segment elevation in V2 of ≥80 ms measured from the J point has a positive predictive value of 37.8% and a negative predictive value of 100% for VF with a 100% sensitivity.
Both criteria are highly specific indicators for VF in this entity.
In a few years, the eponym, Brugada Syndrome, was used nearly unanimously by most investigators. There has been an exponential rise in the number of reported cases and a proliferation of papers serving to define the clinical, genetic, cellular, and molecular aspects of this disease.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Osher HL, Wolff L. Electrocardiographic pattern simulating acute myocardial injury. Am J Med Sci 1953;226:541-5.  |
| 2. | Calo AA. The triad secondary R waves, RS-T segment elevation and T waves inversion in right precordial leads: A normal electrocardiographic variant. G Ital Cardiol 1975;5:955-60. |
| 3. | Vatta M, Dumaine R, Varghese G, Richard TA, Shimizu W, Aihara N, et al. Genetic and biophysical basis of sudden unexplained nocturnal death syndrome (SUNDS), a disease allelic to Brugada syndrome. Hum Mol Genet 2002;11:337-45. |
| 4. | Riera AR, Schapachnik E, Ferreira C. Brugada disease: Chronology of discovery and paternity. Preliminary observations and historical aspects. Indian Pacing Electrophysiol J 2003;3:253-60. |
| 5. | Martini B, Nava A, Thiene G, Buja GF, Canciani B, Scognamiglio R, et al. Ventricular fibrillation without apparent heart disease: Description of six cases. Am Heart J 1989;118:1203-9. |
| 6. | Brugada P, Brugada J. A distinct clinical and electrocardiographic syndrome: Right bundle branch block, persistent ST segment elevation with normal QT interval and sudden cardiac death (abstr). Pacing Clin Electrophysiol 1991;14:746. |
| 7. | Brugada P, Brugada J. Let us do not get confused, please!. G Ital Cardiol 1994;24:797-800. |
| 8. | Yan GX, Antzelevitch C. Cellular Basis for the Brugada Syndrome and Other Mechanisms of Arrhythmogenesis Associated With ST-Segment Elevation. Circulation 1996;93:372-9. |
| 9. | Ikeda T, Sakata T, Sakabe K, et al. Noninvasive risk stratification markers in the Brugada syndrome: Comparison of late potentials, T-wave alternans and QT dispersion. PACE 2000;23:731. |
| 10. | Priori SG, Napolitano C, Gasparini M, Pappone C, Della Bella P, Brignole M, et al. Clinical and genetic heterogeneity of right bundle branch block and ST-segment elevation syndrome: A prospective evaluation of 52 families. Circulation 2000;102:2509-15. |
| 11. | Gussak I, Bjerregaard P, Hammill SC. Clinical diagnosis and risk stratification in patients with Brugada syndrome. J Am Coll Cardiol 2001;37:1635-8. |
| 12. | Vatta M, Dumaine R, Varghese G, Richard TA, Shimizu W, Aihara N, et al. Genetic and biophysical basis of sudden unexplained nocturnal death syndrome (SUNDS), a disease allelic to Brugada syndrome. Hum Mol Genet 2002;11:337-45. |
| 13. | Atarashi H, Ogawa S; Idiopathic Ventricular Fibrillation Investigators. New ECG criteria for high-risk Brugada syndrome. Circ J 2003;67:8-10. |
|
