Abstract：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.
