Synchronization of repolarization by mechano-electrical coupling in the porcine heart
Synchronization of repolarization by mechano-electrical coupling in the porcine heart
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DOI：
10.1093/cvr/cvv140
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发表时间：
2015-10-01
影响因子：
10.8
通讯作者：
Coronel, Ruben
中科院分区：
文献类型：
--
作者：
Opthof, Tobias;Meijborg, Veronique M. F.;Coronel, Ruben
Aims-本研究的目的是评估左心室（LV）压力增加对复极和激动-恢复间期的影响。方法和结果6只猪心脏进行Langendorff灌注。可以填充与压力传感器连接的顺应性液体填充球囊，通过二尖瓣口插入，直到获得所需的LV收缩压。将121个电极（11 x 11; 5 mm电极距离）的网格缝合在LV游离壁上。在600 ms和400或450 ms下从LV壁或从室间隔进行心室起搏。在所有这四种情况下，压力波发生在相对于QRS波群开始的相同时刻。因此，局部复极和压力波之间的时间关系在不同的起搏部位之间不同。复极时间（RT）在600毫秒的周期长度（CL）延长压力增加。对于来自LV的刺激，当压力波与动作电位（AP）在其相位晚期（复极化相对较早的部位）重合时，压力从0增加到100 mmHg延迟的复极化大于来自隔膜的刺激，当压力波发生在AP的相对较早相位时（复极化相对较晚的部位）。在CL 400/450 ms起搏时，心室压力升高可使心室游离壁RT延长，而心室间隔刺激时，心室压力升高可使心室游离壁RT延长或缩短。结论心室压力升高的作用是使心室复极同步化。
Aims The aim of this study was to evaluate the effect of increase in left ventricular (LV) pressure on repolarization and activation-recovery intervals.Methods and results Six pig hearts were Langendorff-perfused. A compliant liquid-filled balloon, connected with a pressure transducer, inserted through the mitral orifice, could be filled until the required LV systolic pressure was obtained. A grid of 121 electrodes (11 x 11; 5 mminterelectrode distance) was sutured on the LV freewall. Ventricular pacing at 600 ms and at 400 or 450 ms was either performed from the LV wall or from the ventricular septum. Under all these four conditions, the pressure wave occurred at the same moment relative to the onset of the QRS complex. Consequently, the time relation between local repolarization and the pressure wave differed between the various pacing sites. Repolarization times (RTs) at a cycle length (CL) of 600 ms were prolonged by increased pressure. With stimulation from the LV, when the pressure wave coincides with the action potentials (APs) late in their phase (sites with relatively early repolarization), an increase in pressure from 0 to 100 mmHg delayed repolarization more than with stimulation from the septum, when the pressure wave occurs at a relatively earlier phase of the AP(sites with relatively late repolarization). At pacing at CL 400/450 ms, an increase in pressure caused RT prolongation at the LV free wall during LV stimulation, but less RT prolongation or even shortening during septal stimulation.Conclusion The effect of increased LV pressure is synchronization of repolarization.