Intracellular calcium dynamics at the core of endocardial stationary spiral waves in Langendorff-perfused rabbit hearts.
Intracellular calcium dynamics at the core of endocardial stationary spiral waves in Langendorff-perfused rabbit hearts.
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Langendorff 灌注兔心脏心内膜静止螺旋波核心的细胞内钙动态。
DOI：
10.1152/ajpheart.00137.2008
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Lin,Shien-Fong
中科院分区：
文献类型：
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作者：
Tang,Liang;Hwang,Gyo-Seung;Hayashi,Hideki;Song,Juan;Ogawa,Masahiro;Kobayashi,Kenzaburo;Joung,Boyoung;Karagueuzian,HrayrS;Chen,Peng-Sheng;Lin,Shien-Fong
持续单形态性室性心动过速（MVT）的体外模型是罕见的，通常不显示心外膜螺旋再入。我们假设MVT与心内膜的螺旋波有关，这种稳定的再入传播是由螺旋波核心持续升高的细胞内钙（Cai）瞬态支持的。我们对langendorff灌注兔心脏（n= 12）右心室（RV）心内膜的跨膜电位（Vm）和Caidynamics进行了双光学作图。在64例诱发性心律失常中，55%为持续MVT （bbb10 min）。80%的MVT在心内膜定位区显示固定的螺旋波（bbb10周期，周期长度：128±14.6 ms），锚定解剖不连续。心外膜未见再入活动。在再入过程中，vm&caisi信号的振幅在外围较高，向核心逐渐降低。在核心部位，vmf和caif的最大值分别为对照组的42.95±5.89%和43.95±9.46% （P< 0.001）。然而，核心的vmand caii信号波谷高于外围，表明在再入期间vmand caii信号持续升高。BAPTA-AM是一种钙螯合剂，可以显著降低caittransient的最大振幅，并阻止在映射区域持续的MVT和螺旋波的形成。这些结果表明，心内膜螺旋波经常锚定在解剖不连续处，导致正常兔心室稳定的MVT。螺旋核心的特征是在再入过程中dv和dv振幅减小和持续升高。
In vitro models of sustained monomorphic ventricular tachycardia (MVT) are rare and do not usually show spiral reentry on the epicardium. We hypothesized that MVT is associated with the spiral wave in the endocardium and that this stable reentrant propagation is supported by a persistently elevated intracellular calcium (Cai) transient at the core of the spiral wave. We performed dual optical mapping of transmembrane potential (Vm) and Caidynamics of the right ventricular (RV) endocardium in Langendorff-perfused rabbit hearts (n= 12). Among 64 induced arrhythmias, 55% were sustained MVT (>10 min). Eighty percent of MVT showed stationary spiral waves (>10 cycles, cycle length: 128 ± 14.6 ms) in the endocardial mapped region, anchoring to the anatomic discontinuities. No reentry activity was observed in the epicardium. During reentry, the amplitudes ofVmand Caisignals were higher in the periphery and gradually decreased toward the core. At the core, maximalVmand Caiamplitudes were 42.95 ± 5.89% and 43.95 ± 9.46%, respectively, of the control (P< 0.001). However, the trough of theVmand Caisignals at the core were higher than those in the periphery, indicating persistentVmand Caielevations during reentry. BAPTA-AM, a calcium chelator, significantly reduced the maximal Caitransient amplitude and prevented sustained MVT and spiral wave formation in the mapped region. These findings indicate that endocardial spiral waves often anchor to anatomic discontinuities causing stable MVT in normal rabbit ventricles. The spiral core is characterized by diminishedVmand Caiamplitudes and persistentVmand Caielevations during reentry.