Study of the State Variation and Neural Control Parameters of the Heart.

摘要

Adopting multi-parameter methods of interpreting pathological changes in the heart over time could improve clinical diagnosis of heart diseases. This study investigated the efficiency of parameters that express heart state variation and neural control. The investigators studied three kinds of parameters (global, local, and dynamic) using different methods to extract physiological and pathological information with animal models. Pathological notch on the QRS complex of electrocardiogram (ECG) is defined as a local parameter that is one of high-frequency components (HFCs). Poincare dispersed- dot plots (PDDP) are defined as nonlinear global parameters. Pathological notching information on the QRS complex is related to myocardial injuries. The authors have been working on man-made myocardial infarction models to simulate cardiac abnormalities. They have found that both myocardial injury methods could produce a good idiosyncratic relationship between the injury area model and man- made pathological conditions. A large number of repetitive experiments with 25 healthy dogs indicated that the thresholds for pathological notching are 84 microvolts in amplitude and 3.8 ms in width. The PDDP was a good parameter of heart nonlinear state and rate variability and has thresholds of about 26000 ms2 in area and 420 ms in long axis for human beings and 600 ms2 in area and 85 ms in long axis for dogs. Both parameters have shown to be sensitive in the early detection of cardiac pathology and also have dynamic characteristics. (2 figures, 9 references).