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Rodríguez -Constaín JS, López-Garzón NA, Navia-Amézquita CA, Mora-Obando DL, Dueñas-Cuellar RA. Síndrome de Brugada. Aspectos fisiopatológicos, clínicos y su asociación con enfermedades infecciosas. IATREIA 2019. [DOI: 10.17533/udea.iatreia.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
El síndrome de Brugada (SBr) es una enfermedad cardiaca no estructural que afecta los canales iónicos cardiacos, caracterizado por manifestaciones clínicas como arritmias, taquicardia, síncope y muerte súbita, entre otras. Su diagnóstico es netamente electrocardiográfico, con un patrón altamente sugestivo pero no patognomónico, por lo que existen diagnósticos diferenciales desde el punto de vista electrocardiográfico.Existen tres patrones electrocardiográficos en los pacientes con SBr, de los cuales el tipo I es el patrón más característico. Actualmente, múltiples genes se han relacionado con la presentación de este síndrome, entre los cuales se destaca el gen SCN5A, el más descrito en la literatura. Se conoce que este síndrome es más frecuente en el género masculino; sin embargo, no existen estudios epidemiológicos en Latinoamérica que lo confirmen. Pese a que la investigación alrededor de los mecanismos causales del síndrome ha avanzado, existen varias cuestiones sin resolver, como su desenmascaramiento por los signos que producen algunas enfermedades infecciosas causadas principalmente por virus. Por lo tanto, dada la relevancia clínica del tema para el médico general y para el especialista, el objetivo de esta revisión es describir no solo aspectos fisiopatológicos y clínicos de la enfermedad, sino también resaltar casos de pacientes con enfermedades infecciosas quienes posteriormente han sido diagnosticados con el síndrome de Brugada.
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Moreau A, Chahine M. A New Cardiac Channelopathy: From Clinical Phenotypes to Molecular Mechanisms Associated With Na v1.5 Gating Pores. Front Cardiovasc Med 2018; 5:139. [PMID: 30356750 PMCID: PMC6189448 DOI: 10.3389/fcvm.2018.00139] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/19/2018] [Indexed: 12/19/2022] Open
Abstract
Voltage gated sodium channels (NaV) are broadly expressed in the human body. They are responsible for the initiation of action potentials in excitable cells. They also underlie several physiological processes such as cognitive, sensitive, motor, and cardiac functions. The NaV1.5 channel is the main NaV expressed in the heart. A dysfunction of this channel is usually associated with the development of pure electrical disorders such as long QT syndrome, Brugada syndrome, sinus node dysfunction, atrial fibrillation, and cardiac conduction disorders. However, mutations of Nav1.5 have recently been linked to the development of an atypical clinical entity combining complex arrhythmias and dilated cardiomyopathy. Although several Nav1.5 mutations have been linked to dilated cardiomyopathy phenotypes, their pathogenic mechanisms remain to be elucidated. The gating pore may constitute a common biophysical defect for all NaV1.5 mutations located in the channel's VSDs. The creation of such a gating pore may disrupt the ionic homeostasis of cardiomyocytes, affecting electrical signals, cell morphology, and cardiac myocyte function. The main objective of this article is to review the concept of gating pores and their role in structural heart diseases and to discuss potential pharmacological treatments.
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Affiliation(s)
- Adrien Moreau
- PhyMedExp, Université de Montpellier, INSERM, CNRS, Montpellier, France
| | - Mohamed Chahine
- CERVO Research Centre, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC, Canada.,Department of Medicine, Université Laval, Quebec City, QC, Canada
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Poulin H, Bruhova I, Timour Q, Theriault O, Beaulieu JM, Frassati D, Chahine M. Fluoxetine blocks Nav1.5 channels via a mechanism similar to that of class 1 antiarrhythmics. Mol Pharmacol 2014; 86:378-89. [PMID: 25028482 PMCID: PMC4164981 DOI: 10.1124/mol.114.093104] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/15/2014] [Indexed: 11/22/2022] Open
Abstract
The voltage-gated Nav1.5 channel is essential for the propagation of action potentials in the heart. Malfunctions of this channel are known to cause hereditary diseases. It is a prime target for class 1 antiarrhythmic drugs and a number of antidepressants. Our study investigated the Nav1.5 blocking properties of fluoxetine, a selective serotonin reuptake inhibitor. Nav1.5 channels were expressed in HEK-293 cells, and Na(+) currents were recorded using the patch-clamp technique. Dose-response curves of racemic fluoxetine (IC50 = 39 μM) and its optical isomers had a similar IC50 [40 and 47 μM for the (+) and (-) isomers, respectively]. Norfluoxetine, a fluoxetine metabolite, had a higher affinity than fluoxetine, with an IC50 of 29 μM. Fluoxetine inhibited currents in a frequency-dependent manner, shifted steady-state inactivation to more hyperpolarized potentials, and slowed the recovery of Nav1.5 from inactivation. Mutating a phenylalanine (F1760) and a tyrosine (Y1767) in the S6 segment of domain (D) IV (DIVS6) significantly reduced the affinity of fluoxetine and its frequency-dependent inhibition. We used a noninactivating Nav1.5 mutant to show that fluoxetine displays open-channel block behavior. The molecular model of fluoxetine in Nav1.5 was in agreement with mutational experiments in which F1760 and Y1767 were found to be the key residues in binding fluoxetine. We concluded that fluoxetine blocks Nav1.5 by binding to the class 1 antiarrhythmic site. The blocking of cardiac Na(+) channels should be taken into consideration when prescribing fluoxetine alone or in association with other drugs that may be cardiotoxic or for patients with conduction disorders.
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Affiliation(s)
- Hugo Poulin
- Centre de recherche, Institut universitaire en santé mentale de Québec, Quebec City, Quebec, Canada (H.P., O.T., J.-M.B., M.C.); State University of New York at Buffalo, Buffalo, New York (I.B.); Laboratoire de Pharmacologie Médicale, EA 4612 Neurocardiologie, Université Lyon 1, Lyon, France (Q.T.); Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Quebec, Canada (J.-M.B.); Pôle Dapela, Département de l'autisme et des psychoses d'évolution lente de l'adulte, Centre Hospitalier Le Vinatier, Bron, France (D.F.); and Department of Medicine, Université Laval, Quebec City, Quebec, Canada (M.C.)
| | - Iva Bruhova
- Centre de recherche, Institut universitaire en santé mentale de Québec, Quebec City, Quebec, Canada (H.P., O.T., J.-M.B., M.C.); State University of New York at Buffalo, Buffalo, New York (I.B.); Laboratoire de Pharmacologie Médicale, EA 4612 Neurocardiologie, Université Lyon 1, Lyon, France (Q.T.); Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Quebec, Canada (J.-M.B.); Pôle Dapela, Département de l'autisme et des psychoses d'évolution lente de l'adulte, Centre Hospitalier Le Vinatier, Bron, France (D.F.); and Department of Medicine, Université Laval, Quebec City, Quebec, Canada (M.C.)
| | - Quadiri Timour
- Centre de recherche, Institut universitaire en santé mentale de Québec, Quebec City, Quebec, Canada (H.P., O.T., J.-M.B., M.C.); State University of New York at Buffalo, Buffalo, New York (I.B.); Laboratoire de Pharmacologie Médicale, EA 4612 Neurocardiologie, Université Lyon 1, Lyon, France (Q.T.); Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Quebec, Canada (J.-M.B.); Pôle Dapela, Département de l'autisme et des psychoses d'évolution lente de l'adulte, Centre Hospitalier Le Vinatier, Bron, France (D.F.); and Department of Medicine, Université Laval, Quebec City, Quebec, Canada (M.C.)
| | - Olivier Theriault
- Centre de recherche, Institut universitaire en santé mentale de Québec, Quebec City, Quebec, Canada (H.P., O.T., J.-M.B., M.C.); State University of New York at Buffalo, Buffalo, New York (I.B.); Laboratoire de Pharmacologie Médicale, EA 4612 Neurocardiologie, Université Lyon 1, Lyon, France (Q.T.); Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Quebec, Canada (J.-M.B.); Pôle Dapela, Département de l'autisme et des psychoses d'évolution lente de l'adulte, Centre Hospitalier Le Vinatier, Bron, France (D.F.); and Department of Medicine, Université Laval, Quebec City, Quebec, Canada (M.C.)
| | - Jean-Martin Beaulieu
- Centre de recherche, Institut universitaire en santé mentale de Québec, Quebec City, Quebec, Canada (H.P., O.T., J.-M.B., M.C.); State University of New York at Buffalo, Buffalo, New York (I.B.); Laboratoire de Pharmacologie Médicale, EA 4612 Neurocardiologie, Université Lyon 1, Lyon, France (Q.T.); Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Quebec, Canada (J.-M.B.); Pôle Dapela, Département de l'autisme et des psychoses d'évolution lente de l'adulte, Centre Hospitalier Le Vinatier, Bron, France (D.F.); and Department of Medicine, Université Laval, Quebec City, Quebec, Canada (M.C.)
| | - Dominique Frassati
- Centre de recherche, Institut universitaire en santé mentale de Québec, Quebec City, Quebec, Canada (H.P., O.T., J.-M.B., M.C.); State University of New York at Buffalo, Buffalo, New York (I.B.); Laboratoire de Pharmacologie Médicale, EA 4612 Neurocardiologie, Université Lyon 1, Lyon, France (Q.T.); Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Quebec, Canada (J.-M.B.); Pôle Dapela, Département de l'autisme et des psychoses d'évolution lente de l'adulte, Centre Hospitalier Le Vinatier, Bron, France (D.F.); and Department of Medicine, Université Laval, Quebec City, Quebec, Canada (M.C.)
| | - Mohamed Chahine
- Centre de recherche, Institut universitaire en santé mentale de Québec, Quebec City, Quebec, Canada (H.P., O.T., J.-M.B., M.C.); State University of New York at Buffalo, Buffalo, New York (I.B.); Laboratoire de Pharmacologie Médicale, EA 4612 Neurocardiologie, Université Lyon 1, Lyon, France (Q.T.); Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Quebec, Canada (J.-M.B.); Pôle Dapela, Département de l'autisme et des psychoses d'évolution lente de l'adulte, Centre Hospitalier Le Vinatier, Bron, France (D.F.); and Department of Medicine, Université Laval, Quebec City, Quebec, Canada (M.C.)
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