Zhang Hong, Jin Yinbin, Zhao Wei, Yang Lin
School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, China
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2010 Jun;27(3):485-9.
Ventricular fibrillation (VF) is the main cause of sudden death in cardiovascular diseases. The effects of electrophysiological heterogeneity and dynamic factors bring a lot of difficulties in understanding and revealing the mechanisms of VF. Cardiac short-term memory is one of the factors that make invalidation of restitution curve slope as the criteria for transition from ventricular tachycardia to VF. Therefore, investigation of inherent properties of short-term memory and its role in VF has great significance. In this paper we took advantage of the perturbed down-sweep protocol to measure dynamic and local S1S2 restitution curves on three widely used mathematical models to reveal their memory property. And by making abrupt change of the stimulation cycle length, we examined the attenuation process of the memory. The results showed, the rate-dependent action potendial duration (APD) is related with S1 pacing. The APD difference under different S2 cycle length is more pronounced with short S1 cycle length. Except the Luo-Rudy 1991 model, the Luo-Rudy 1994 and Noble 1991 models can at least reflect some of the short-term memory. And the memory attenuated in exponential way. Therefore, in quantitative electrophysiological study, these two models can be used in the future for investigating the characteristics of the short-term memory and its contribution to VF.
心室颤动（VF）是心血管疾病猝死的主要原因。电生理异质性和动态因素的影响给理解和揭示VF机制带来诸多困难。心脏短期记忆是使恢复曲线斜率失效作为室性心动过速转变为VF标准的因素之一。因此，研究短期记忆的固有特性及其在VF中的作用具有重要意义。本文利用微扰下扫协议在三个广泛使用的数学模型上测量动态和局部S1S2恢复曲线，以揭示它们的记忆特性。并且通过突然改变刺激周期长度，我们研究了记忆的衰减过程。结果表明，频率依赖性动作电位时程（APD）与S1起搏有关。在不同S2周期长度下，APD差异在短S1周期长度时更为明显。除了Luo-Rudy 1991模型外，Luo-Rudy 1994和Noble 1991模型至少能反映一些短期记忆。并且记忆以指数方式衰减。因此，在定量电生理研究中，这两个模型未来可用于研究短期记忆的特征及其对VF的贡献。
