ST segment elevation by current-to-load mismatch: an experimental and computational study
ST segment elevation by current-to-load mismatch: an experimental and computational study
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DOI：
10.1016/j.hrthm.2010.09.066
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发表时间：
2011-01-01
期刊：
影响因子：
5.5
通讯作者：
Coronel, Ruben
中科院分区：
文献类型：
--
作者：
Hoogendijk, Mark G.;Potse, Mark;Coronel, Ruben
背景最近，我们证实，在结构不连续的心肌中，由于兴奋失败，阿曲库铵导致SCN 5A突变携带者心脏ST段抬高。Brugada综合征患者的ST段抬高受心脏钠电流（I-Na）、瞬时外向电流（I-to）和L型钙电流（I-CaL）的调节。目的通过实验确定电流-负荷不匹配引起的兴奋失败是否会引起ST段抬高，以及是否受I-to和I-CaL的调节。或1.3mm宽的纤维束平行于纤维取向形成。局部激活记录电或光学（di-4ANEPPS）与伪心电图（ECG）之前和之后ajabrixate应用。在计算机模型中模拟右心室结构不连续前后及不同水平的I-Na、I-to和I-CaL时的心内和细胞外电位及心电图。结果在心外膜刨削片中，所有峡部≤ 1.1mm的标本，在心房颤动后均出现频率依赖性传导阻滞（P
BACKGROUND Recently, we demonstrated that ajmaline caused ST segment elevation in the heart of an SCN5A mutation carrier by excitation failure in structurally discontinuous myocardium. In patients with Brugada syndrome, ST segment elevation is modulated by cardiac sodium (I-Na), transient outward (I-to), and L-type calcium currents (I-CaL).OBJECTIVE To establish experimentally whether excitation failure by current-to-load mismatch causes ST segment elevation and is modulated by I-to and I-CaL.METHODS In porcine epicardial shavings, isthmuses of 0.9, 1.1, or 1.3 mm in width were created parallel to the fiber orientation. Local activation was recorded electrically or optically (di-4ANEPPS) simultaneously with a pseudo-electrocardiogram (ECG) before and after ajmaline application. Intra-and extracellular potentials and ECGs were simulated in a computer model of the heart and thorax before and after introduction of right ventricular structural discontinuities and during varying levels of I-Na, I-to, and I-CaL.RESULTS In epicardial shavings, conduction blocked after ajmaline in a frequency-dependent manner in all preparations with isthmuses = 1.1 mm (P