Oscillation in cycle length induces transient discordant and steady-state concordant alternans in the heart.
Oscillation in cycle length induces transient discordant and steady-state concordant alternans in the heart.
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DOI：
10.1371/journal.pone.0040477
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Tung L
中科院分区：
文献类型：
--
作者：
Weinberg SH;Tung L
交替是心脏动作电位时程（APD）或细胞内钙离子（Cai）瞬变的一种心跳间交替。在心脏组织中，交替可以是空间一致的或不一致的，其中后者已被证明增加复极的离散度并促进心室颤动起始的底物。几乎只在恒定周期长度起搏条件下研究交替。然而，在正常和病理条件下，心率在逐搏的基础上变化很大。本研究的目的是确定应用重复但不恒定的起搏模式，特别是周期长度振荡（CLO），是否促进或抑制了促心律失常底物。我们进行了计算模拟和光学映射实验，以调查CLO的潜在后果。在单细胞计算模型中，CLO诱导APD和Cai交替，其与施加的振荡变得“相位匹配”。作为一个结果的相位匹配，在一维电缆模拟，新生大鼠心室肌细胞单层，和孤立的成年豚鼠心脏CLO可以短暂诱导空间和机电不协调交替，然后由一个稳定的状态的一致性。结果表明，在一定条件下，CLO可引起离体心脏的室颤。另一方面，CLO还可以通过将不协调交替的存在状态转化为协调交替来发挥抗肿瘤作用。
Alternans is a beat-to-beat alternation of the cardiac action potential duration (APD) or intracellular calcium (Cai) transient. In cardiac tissue, alternans can be spatially concordant or discordant, of which the latter has been shown to increase dispersion of repolarization and promote a substrate for initiation of ventricular fibrillation. Alternans has been studied almost exclusively under constant cycle length pacing conditions. However, heart rate varies greatly on a beat-by-beat basis in normal and pathological conditions. The purpose of this study was to determine if applying a repetitive but non-constant pacing pattern, specifically cycle length oscillation (CLO), promotes or suppresses a proarrhythmic substrate. We performed computational simulations and optical mapping experiments to investigate the potential consequences of CLO. In a single cell computational model, CLO induced APD and Cai alternans, which became “phase-matched” with the applied oscillation. As a consequence of the phase-matching, in one-dimensional cable simulations, neonatal rat ventricular myocyte monolayers, and isolated adult guinea pig hearts CLO could transiently induce spatial and electromechanical discordant alternans followed by a steady-state of concordance. Our results demonstrated that under certain conditions, CLO can initiate ventricular fibrillation in the isolated hearts. On the other hand, CLO can also exert an antiarrhythmic effect by converting an existing state of discordant alternans to concordant alternans.
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影响因子：
2.4
作者：
Shiferaw, Y;Sato, D;Karma, A
通讯作者：
Karma, A
DOI：
10.1073/pnas.091553398
发表时间：
2001-05-08
影响因子：
11.1
作者：
Christini, DJ;Stein, KM;Lerman, BB
通讯作者：
Lerman, BB
影响因子：
2.4
作者：
Otani, Niels F.
通讯作者：
Otani, Niels F.
DOI：
10.1046/j.1540-8167.2001.00196.x
发表时间：
2001-02-01
影响因子：
2.7
作者：
Watanabe, MA;Fenton, FH;Karma, A
通讯作者：
Karma, A
DOI：
10.1111/j.1540-8167.2005.00319.x
发表时间：
2006-01-01
影响因子：
2.7
作者：
Wu, RZ;Patwardhan, A
通讯作者：
Patwardhan, A