Abstract
In this paper we propose a model of the dynamic heart system, as a necessary and important element of the non-invasive ECG diagnostic system. It was shown that the conceptual and detailed models of heart electrical activity are the link for all the subsystems of the cardiovascular system. In this case the ECG provides information of the status and autowave processes in a dynamic heart system. To control the state of the dynamic heart system, method, based on the evaluation information and probability of ECG characteristics for the sample values in a sliding window that has size of one cardiocycle, is proposed.