Multifocal Ectopic Purkinje-Related Premature Contractions: A New SCN5A-Related Cardiac Channelopathy. - Inserm - Institut national de la santé et de la recherche médicale Accéder directement au contenu
Article Dans Une Revue Journal of the American College of Cardiology Année : 2012

Multifocal Ectopic Purkinje-Related Premature Contractions: A New SCN5A-Related Cardiac Channelopathy.

Olivier Barthez
Véronique Fressart
Yves Coudière

Résumé

OBJECTIVES: The aim of this study was to describe a new familial cardiac phenotype and to elucidate the electrophysiological mechanism responsible for the disease. BACKGROUND: Mutations in several genes encoding ion channels, especially SCN5A, have emerged as the basis for a variety of inherited cardiac arrhythmias. METHODS: Three unrelated families comprising 21 individuals affected by multifocal ectopic Purkinje-related premature contractions (MEPPC) characterized by narrow junctional and rare sinus beats competing with numerous premature ventricular contractions with right and/or left bundle branch block patterns were identified. RESULTS: Dilated cardiomyopathy was identified in 6 patients, atrial arrhythmias were detected in 9 patients, and sudden death was reported in 5 individuals. Invasive electrophysiological studies demonstrated that premature ventricular complexes originated from the Purkinje tissue. Hydroquinidine treatment dramatically decreased the number of premature ventricular complexes. It normalized the contractile function in 2 patients. All the affected subjects carried the c.665G>A transition in the SCN5A gene. Patch-clamp studies of resulting p.Arg222Gln (R222Q) Nav1.5 revealed a net gain of function of the sodium channel, leading, in silico, to incomplete repolarization in Purkinje cells responsible for premature ventricular action potentials. In vitro and in silico studies recapitulated the normalization of the ventricular action potentials in the presence of quinidine. CONCLUSIONS: A new SCN5A-related cardiac syndrome, MEPPC, was identified. The SCN5A mutation leads to a gain of function of the sodium channel responsible for hyperexcitability of the fascicular-Purkinje system. The MEPPC syndrome is responsive to hydroquinidine.
Fichier principal
Vignette du fichier
Laurent_et_al._JACC_2012_suppl.pdf (1.71 Mo) Télécharger le fichier
Laurent_et_al._JACC_2012.pdf (1.35 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

inserm-00719034 , version 1 (18-07-2012)

Identifiants

Citer

Gabriel Laurent, Samuel Saal, Mohamed Yassine Amarouch, Delphine M. Béziau, Roos F. J. Marsman, et al.. Multifocal Ectopic Purkinje-Related Premature Contractions: A New SCN5A-Related Cardiac Channelopathy.: MEPPC: a new SCN5A-related cardiac channelopathy. Journal of the American College of Cardiology, 2012, 60 (2), pp.144-56. ⟨10.1016/j.jacc.2012.02.052⟩. ⟨inserm-00719034⟩
980 Consultations
1449 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More