Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
PLoS One. 2012;7(8):e42037. doi: 10.1371/journal.pone.0042037. Epub 2012 Aug 2.
The cardiac sodium channel (Na(v)1.5) controls cardiac excitability. Accordingly, SCN5A mutations that result in loss-of-function of Na(v)1.5 are associated with various inherited arrhythmia syndromes that revolve around reduced cardiac excitability, most notably Brugada syndrome (BrS). Experimental studies have indicated that Na(v)1.5 interacts with the cytoskeleton and may also be involved in maintaining structural integrity of the heart. We aimed to determine whether clinical evidence may be obtained that Na(v)1.5 is involved in maintaining cardiac structural integrity.
Using cardiac magnetic resonance (CMR) imaging, we compared right ventricular (RV) and left ventricular (LV) dimensions and ejection fractions between 40 BrS patients with SCN5A mutations (SCN5a-mut-positive) and 98 BrS patients without SCN5A mutations (SCN5a-mut-negative). We also studied 18 age/sex-matched healthy volunteers.
SCN5a-mut-positive patients had significantly larger end-diastolic and end-systolic RV and LV volumes, and lower LV ejection fractions, than SCN5a-mut-negative patients or volunteers.
Loss-of-function SCN5A mutations are associated with dilatation and impairment in contractile function of both ventricles that can be detected by CMR analysis.
心脏钠离子通道（Na(v)1.5）控制着心脏的兴奋性。因此，导致 Na(v)1.5 功能丧失的 SCN5A 突变与各种遗传性心律失常综合征有关，这些综合征围绕着心脏兴奋性降低展开，其中最著名的是 Brugada 综合征（BrS）。实验研究表明，Na(v)1.5 与细胞骨架相互作用，并且可能还参与维持心脏的结构完整性。我们旨在确定是否可以获得临床证据表明 Na(v)1.5 参与维持心脏结构完整性。
我们使用心脏磁共振（CMR）成像，比较了 40 名携带 SCN5A 突变（SCN5a-mut-阳性）的 BrS 患者与 98 名无 SCN5A 突变（SCN5a-mut-阴性）的 BrS 患者以及 18 名年龄/性别匹配的健康志愿者的右心室（RV）和左心室（LV）的尺寸和射血分数。
SCN5a-mut-阳性患者的 RV 和 LV 舒张末期和收缩末期容积明显大于 SCN5a-mut-阴性患者或志愿者，LV 射血分数也较低。
功能丧失的 SCN5A 突变与心室扩张和收缩功能障碍有关，CMR 分析可检测到这些变化。
