Rapid ventricular repolarization in rodents: Electrocardiographic manifestations, molecular mechanisms, and clinical insights
Rapid ventricular repolarization in rodents: Electrocardiographic manifestations, molecular mechanisms, and clinical insights
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DOI：
10.1016/s0022-0736(00)80072-2
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发表时间：
2000-04-01
影响因子：
1.3
通讯作者：
Nerbonne, JM
中科院分区：
文献类型：
--
作者：
Gussak, I;Chaitman, BR;Nerbonne, JM
本文研究了大鼠和小鼠心室复极的特定心电图（ECG）和电生理特征，以及去极化激活钾电流在介导这些啮齿动物ECG记录的独特特征中的作用。本文描述了这些啮齿类动物心室复极的基础电流，确定了适当描述小鼠ECG记录独特特征的术语，并将这些独特发现与选定的人类ECG心室复极异常联系起来。QRS复合体和T波之间没有明显的等电间隔，并伴有相对较短的QT间期，这是小鼠和大鼠心电图记录的共同特征，但在豚鼠心电图中却没有。小鼠的心电图形态显然是由于在心室复极的早期阶段存在大量向外的K+电流。在大鼠和小鼠中，复极化早期的主要电流似乎是快速激活和灭活4-氨基吡啶敏感的瞬时外向电流（即I-to）。重要的是，大鼠和小鼠的I-to密度很高，而在豚鼠的心室肌细胞中这种电流并不明显。高密度的I-to似乎是大鼠和小鼠明显的J波或向下倾斜的st段抬高的基础，而豚鼠的st段是等电的。然而，小鼠心电图中不寻常的J波和st段模式确实与Brugada综合征、低体温和缺血患者的心电图特征有一些相似之处。因此，大鼠和小鼠的这些模式可能作为特发性J波的实验模型。
This article examines specific electrocardiographic (ECG) and electrophysiological features of ventricular repolarization in rats and mice, and the role of depolarization-activated potassium currents in mediating the unique features of ECG recordings in these rodents. This article describes the currents that underlie ventricular repolarization in these rodents, identifies terminology that appropriately describes the unique features of murine ECG recordings, and correlates these unique findings with selected human ECG ventricular repolarization abnormalities. The absence of a distinct isoelectric interval between the QRS complex and the T wave, accompanied by a relatively short QT interval, are common features of ECG recordings in mice and rats, but nor in ECGs in guinea pigs. The murine ECG morphology is apparently attributable to the presence of large outward K+ currents that dominate the early phase of ventricular repolarization. In rats and mice, the predominant current under lying the early phase of repolarization appears to be the rapidly activating and inactivating 4-aminopyridine-sensitive transient outward current (ie, I-to). Importantly, the density of I-to in rats and mice is high, whereas this current is not evident in the ventricular myocytes of guinea pigs. The high density of I-to appears to underlie the prominent J wave or downsloping ST-segment elevation seen in rats and mice, whereas the ST-segment is isoelectric in guinea pigs. The unusual J wave and ST-segment pattern in murine ECGs, however, does bear some resemblance to ECG features observed in humans with Brugada syndrome, and with hypothermia and ischemia. These patterns in rats and mice might, therefore, serve as an experimental model for the idiopathic J wave.