Facilitatory and inhibitory effects of SCN5A mutations on atrial fibrillation in Brugada syndrome
Facilitatory and inhibitory effects of SCN5A mutations on atrial fibrillation in Brugada syndrome
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DOI：
10.1093/europace/eur011
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发表时间：
2011-07-01
期刊：
影响因子：
6.1
通讯作者：
Tan, Hanno L.
中科院分区：
文献类型：
--
作者：
Amin, Ahmad S.;Boink, Gerard J. J.;Tan, Hanno L.
布鲁格达综合征 (BrS) 与心房颤动 (AFib) 风险增加相关。然而，SCN5A 突变在 AFib 发生中的作用仍不清楚。 SCN5A 突变引起的心脏钠电流减少可能通过减慢心房传导和诱导结构变化而促进 AFib，但也可以通过抑制心房异位活动来预防 AFib。在这里，我们检查了 BrS 中 SCN5A 突变、心房传导速度、心房结构变化和心房异位活动之间的关系。方法和结果来自 214 名 BrS 患者的数据 [78 名有 SCN5A 突变的患者（有 SCN5A 突变的患者，BrS(SCN5A+)）和 136 名没有 SCN5A 突变的患者（没有 SCN5A 突变的患者，BrS(SCN5A-)）]被收集。通过测量基线和钠通道激发测试期间的 P 波持续时间来评估心房内传导速度。通过使用心脏磁共振成像测量心房尺寸来评估心房结构变化。通过使用 24 小时动态心电图记录确定心房异位搏动的发生率来评估心房异位活动。 BrS(SCN5A+) 和 BrS(SCN5A-) 的临床特征（包括 AFib 发生）没有差异。 BrS(SCN5A+) 中的基线 P 波持续时间比 BrS(SCN5A-) 中的更长，但在激发测试期间 BrS(SCN5A-) 中的基线 P 波持续时间显着延长。心房尺寸没有差异。 BrS(SCN5A-)中心房异位搏动的发生率更高，并且BrS(SCN5A-)中经历一次或多次心房异位搏动的患者比例比BrS(SCN5A+)中更大。结论在BrS中，SCN5A突变的存在与心房内传导减慢和心房异位活动抑制相关。心房内传导减慢可能为 AFib 维持提供合理的基础，而心房异位活动的减少可能构成对 AFib 启动触发的抑制。
Aims Brugada syndrome (BrS) is associated with increased risk for atrial fibrillation (AFib). However, the role of SCN5A mutations in the occurrence of AFib remains unclear. Cardiac sodium current reduction caused by SCN5A mutations may facilitate AFib by slowing intra-atrial conduction and inducing structural changes, but also prevent it by suppressing atrial ectopic activity. Here, we examined the relation between SCN5A mutations, atrial conduction velocity, atrial structural changes, and atrial ectopic activity in BrS.Methods and results Data from 214 BrS patients [78 with an SCN5A mutation (patients with an SCN5A mutation, BrS(SCN5A+)) and 136 without an SCN5A mutation (patients without an SCN5A mutation, BrS(SCN5A-))] were collected. Intra-atrial conduction velocity was assessed by measuring P-wave durations at baseline and during sodium channel provocation testing. Atrial structural changes were assessed by measuring atrial dimensions using cardiac magnetic resonance imaging. Atrial ectopic activity was assessed by determining the incidence of atrial ectopic beats using 24 h Holter recordings. Clinical characteristics (including AFib occurrence) did not differ between BrS(SCN5A+) and BrS(SCN5A-). Baseline P-wave durations were longer in BrS(SCN5A+) than in BrS(SCN5A-), but lengthened markedly in BrS(SCN5A-) during provocation testing. Atrial dimensions did not differ. Atrial ectopic beats occurred more often in BrS(SCN5A-), and the proportion of patients experiencing one or more atrial ectopic beats was larger in BrS(SCN5A-) than in BrS(SCN5A+).Conclusion In BrS, the presence of an SCN5A mutation is associated with intra-atrial conduction slowing and suppressed atrial ectopic activity. Intra-atrial conduction slowing may provide a plausible substrate for AFib maintenance, while reduced atrial ectopic activity may constitute inhibition of the trigger for AFib initiation.