Sangawa Mutsuko, Morita Hiroshi, Nakatsu Takaaki, Nishii Nobuhiro, Miura Daiji, Miura Aya, Tada Takeshi, Murakami Masato, Hiramatsu Shigeki, Nagase Satoshi, Nakamura Kazufumi, Oka Takefumi, Toyonaga Shinji, Mashima Keiichi, Kusachi Shozo, Yamamoto Kazuhide, Ohe Tohru, Kusano Kengo F
Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry, Okayama City, Okayama, Japan.
Heart Rhythm. 2009 Aug;6(8):1163-9. doi: 10.1016/j.hrthm.2009.04.037. Epub 2009 May 4.
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.
复极异常，尤其是在心动过缓期间，可能是Brugada综合征（BrS）患者发生心室颤动（VF）的关键因素，但心率依赖性复极动力学对VF发生的作用仍不清楚。
我们研究的目的是确定有自发VF和无自发VF的BrS患者之间以及有SCN5A突变和无SCN5A突变的BrS患者之间心率依赖性复极动力学的差异。
研究对象为37例BrS患者，其中有VF的患者（VF(+)组：10例男性）和无VF的患者（VF(-)组：27例男性）以及20例对照者。对所有37例BrS患者进行SCN5A基因分析。从动态心电图记录中获取QT、QTp、Tp-e和RR间期之间的关系作为最初的线性回归线，并比较QT/RR、QTp/RR和Tp-e/RR线性回归线的斜率作为心率依赖性复极动力学的敏感性。
与VF(-)组和对照组相比，VF(+)组的QT/RR和Tp-e/RR斜率显示出心率依赖性特性的丧失。VF(+)组、VF(-)组和对照组之间的QTp/RR斜率无显著差异。VF(+)组中Tp-e间期与RR间期呈负相关，VF(-)组和对照组中Tp-e间期与RR间期呈正相关。有SCN5A突变和无SCN5A突变的BrS患者之间的QT/RR、QTp/RR和Tp-e/RR斜率无显著差异。
心率依赖性QT动力学的丧失可能与BrS患者发生VF有关。
