Referenced in: none

Automatically associated channels: Nav1.5 , Slo1

Title: Abnormal transmural repolarization process in patients with Brugada syndrome.

Authors: Mutsuko Sangawa, Hiroshi Morita, Takaaki Nakatsu, Nobuhiro Nishii, Daiji Miura, Aya Miura, Takeshi Tada, Masato Murakami, Shigeki Hiramatsu, Satoshi Nagase, Kazufumi Nakamura, Takefumi Oka, Shinji Toyonaga, Keiichi Mashima, Shozo Kusachi, Kazuhide Yamamoto, Tohru Ohe, Kengo F Kusano

Journal, date & volume: Heart Rhythm, 2009 Aug , 6, 1163-9

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/19632628

Abstract
Repolarization abnormality, especially during bradycardia, might be critical for initiation of ventricular fibrillation (VF) in patients with Brugada syndrome (BrS), but the contribution of the rate-dependent repolarization dynamics to the occurrence of VF is still unknown.The aim of our study was to determine the differences in rate-dependent repolarization dynamics between BrS with and without spontaneous VF and between BrS with and without SCN5A mutation.The subjects were 37 BrS patients with VF (VF(+) group: 10 male subjects) and without VF (VF(-) group: 27 male subjects) and 20 control subjects. Genetic analysis of SCN5A was performed in all 37 BrS patients. The relationships between QT, QTp, Tp-e, and RR intervals were obtained from Holter recordings as first linear regression lines, and the slopes of QT/RR, QTp/RR, and Tp-e/RR linear regression lines as the sensitivity of rate-dependent repolarization dynamics were compared.QT/RR and Tp-e/RR slopes showed loss of a rate-dependent property in the VF(+) group compared with those in the VF(-) and control groups. There was no significant difference in QTp/RR slope among the VF(+), VF(-) and control groups. The Tp-e interval had a negative correlation with the RR interval in the VF(+) group and a positive correlation with the RR interval in the VF(-) and control groups. There was no significant difference in QT/RR, QTp/RR, and Tp-e/RR slopes between BrS patients with SCN5A mutation and those without SCN5A mutation.Loss of rate-dependent QT dynamics may be associated with occurrence of VF in BrS.