Brugada Syndrome; Hypokalemia; Hypokalemic Periodic Paralysis
Dear Editor,
We read with great interest the case report by Gazzoni et al11. Gazzoni GF, Borges AP, Bergoli LC, Soares JL, Kalil C, Bartholomay E.
Brugada-like electrocardiographic changes induced by hypokalemia. Arq Bras Cardiol.
2013;100(3):e35-7. regarding a Brugada ECG pattern induced by hypokalemia. This
paper is important because it contributes to the growing body of literature
describing Brugada Phenocopies (BrP)22. Baranchuk A, Nguyen T, Ryu MH, Femenía F, Zareba W, Wilde AA, et al.
Brugada phenocopy: new terminology and proposed classification. Ann Noninvasive
Electrocardiol. 2012;17(4):299-314.
3. Anselm DD, Baranchuk A. Brugada Phenocopy: redefinition and updated
classification. Am J Cardiol. 2013;111(3):453.
4. Anselm DD, Baranchuk A. Brugada Phenocopy in the context of pulmonary
embolism. Int J Cardiol. Feb 25. [Epub ahead of print].-55. Anselm DD, Baranchuk A. Brugada Phenocopy Emerging as a New Concept.
Rev Esp Cardiol. 2013;66(9):755..
Briefly, BrP are characterized by ECG patterns that are identical to type-1 or type-2
Brugada ECG patterns despite the absence of true congenital Brugada Syndrome (BrS).
BrP are induced by various clinical circumstances including: hypokalemia,
hyperkalemia, hypothermia, myocardial ischemia, and pulmonary embolism. We have
established six etiological categories of BrP22. Baranchuk A, Nguyen T, Ryu MH, Femenía F, Zareba W, Wilde AA, et al.
Brugada phenocopy: new terminology and proposed classification. Ann Noninvasive
Electrocardiol. 2012;17(4):299-314.
3. Anselm DD, Baranchuk A. Brugada Phenocopy: redefinition and updated
classification. Am J Cardiol. 2013;111(3):453.-44. Anselm DD, Baranchuk A. Brugada Phenocopy in the context of pulmonary
embolism. Int J Cardiol. Feb 25. [Epub ahead of print]. along with a
systematic approach to diagnose BrP33. Anselm DD, Baranchuk A. Brugada Phenocopy: redefinition and updated
classification. Am J Cardiol. 2013;111(3):453. by
excluding sodium channel dysfunction in the myocardium. The presented case by Gazzoni
et al11. Gazzoni GF, Borges AP, Bergoli LC, Soares JL, Kalil C, Bartholomay E.
Brugada-like electrocardiographic changes induced by hypokalemia. Arq Bras Cardiol.
2013;100(3):e35-7. would possibly qualify under category
(i) metabolic conditions; however, further analysis of this case report is
required.
Specifically, this is the first report of a possible BrP induced by hypokalemia in association with hypokalemic periodic paralysis (HPP). Patients with HPP are known to have gene mutations resulting in abnormalities of either dihydropyridine sensitive calcium channels or sodium channels (SCN4A) in skeletal muscles. Patients with true congenital BrS have mutations in the myocardial sodium channels (SCN5A) and the association in this patient is most intriguing and remains speculative. The type-1 "coved" Brugada ECG pattern observed in this patient could have been induced by the transient serum hypokalemia (which would qualify this as a BrP) or there may be a congenital dysfunction in this patient's sodium channels in both his skeletal muscles (HPP) and myocardium resulting in the ECG abnormalities. Therefore, we recommend to the authors that a myocardial provocative challenge with a sodium channel blocker such as procainamide, ajmaline, or flecainide be performed to rule out myocardial sodium channel dysfunction. In addition, we also suggest that future reports use the established term Brugada Phenocopy to provide consistency in the literature and facilitate future research.
We are establishing an international registry database at www.burgadaphenocopy.com and invite Gazzoni et al11. Gazzoni GF, Borges AP, Bergoli LC, Soares JL, Kalil C, Bartholomay E. Brugada-like electrocardiographic changes induced by hypokalemia. Arq Bras Cardiol. 2013;100(3):e35-7. to submit this case along with future cases to the registry should they satisfy the BrP diagnostic criteria33. Anselm DD, Baranchuk A. Brugada Phenocopy: redefinition and updated classification. Am J Cardiol. 2013;111(3):453.. The goal of this registry is to provide long-term follow-up and insight into the pathophysiology and natural history of patients presenting with BrP.
Referências
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1Gazzoni GF, Borges AP, Bergoli LC, Soares JL, Kalil C, Bartholomay E. Brugada-like electrocardiographic changes induced by hypokalemia. Arq Bras Cardiol. 2013;100(3):e35-7.
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2Baranchuk A, Nguyen T, Ryu MH, Femenía F, Zareba W, Wilde AA, et al. Brugada phenocopy: new terminology and proposed classification. Ann Noninvasive Electrocardiol. 2012;17(4):299-314.
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3Anselm DD, Baranchuk A. Brugada Phenocopy: redefinition and updated classification. Am J Cardiol. 2013;111(3):453.
-
4Anselm DD, Baranchuk A. Brugada Phenocopy in the context of pulmonary embolism. Int J Cardiol. Feb 25. [Epub ahead of print].
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5Anselm DD, Baranchuk A. Brugada Phenocopy Emerging as a New Concept. Rev Esp Cardiol. 2013;66(9):755.
Publication Dates
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Publication in this collection
Jan 2014
History
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Received
01 June 2013 -
Reviewed
12 June 2013 -
Accepted
23 July 2013