兔心肌缺血再灌注损伤后心功能与心率变异性的非线性动力学分析的研究

目的　探讨兔心肌缺血再灌注损伤后，心功能与心率变异（ＨＲＶ） 非线性动力学分析的关系。方法　采用结扎新西兰兔左冠状动脉前降支的方法制备缺血再灌注动物模型，用电磁血流量计测量心输出量，应用美国物理学会出版的Ｃｈｏａｓ Ｄａｔａ Ａｎａｌｙｚｅｒ（ＣＤＡ） 软件对所采集的ＨＲＶ 进行非线性动力学分析，并与心排血量比较，分析其相关性。结果　①左冠状动脉前降支结扎后ＨＲＶ 的非线性动力学各指标（ 除关联维外） 与结扎前相比均明显降低（ Ｐ＜０ ．０５）。结扎前后复杂度、熵、李氏指数及关联维分别为０ ．６６ ±０．１１ ，０ ．５０ ±０ ．０８ ，０．１６±０．０３，５．４７ ±０．４５；０ ．４１ ±０ ．１１ ，０ ．４４ ±０ ．０５ ，０ ．１２ ±０ ．０４ 及５ ．３７ ±０．５０ ；②再灌注组与缺血组，及再灌注前后比较各指标均无明显差异（ Ｐ＞０ ．０５） ；③复杂度、熵和李雅普诺夫指数与心输出量呈正相关（Ｐ＜ ０．０１）。结论　非线性动力学指标可以反映心肌缺血及心功能的改变。

Relationship between the cardiac function and nonlinear dynamics analysis of the heart rate variability signal in rabbits with myocardial ischemia and reperfusion

Objective To study the relationship between the cardiac function and nonlinear dynamics analysis of the heart rate variability (HRV) signal. Methods A rabbit model of myocardial ischemia and reperfusion was established by ligating the anterior descending coronary artery. HRV nonlinear dynamics indices were obtained by the chaos data analyzer and compared with the cardiac output. Results Except correlation dimension, the indices of HRV nonlinear dynamics, including complexity, entropy and lyapunov exponent, significantly decreased from 0.66±0.11, 0.50±0.08, and 0.16±0.03 pre-occlusion to 0.41±0.11, 0.44±0.05, and 0.12±0.04 post-occlusion, respectively. The change of these indices linearly correlated with the decline of the cardiac output induced by ischemia (r=0.71, 0.59, and 0.58, P<0.01). Conclusions The HRV nonlinear dynamics method may be a useful tool for evaluating the cardiac function during myocardial ischemia.