A recently developed method for diagnostic of phase synchronization between several oscillatory processes from one-dimensional signals alone was extended and applied to the blood pressure signal of freely moving rats. Each rat examined has undergone four stages: 1) healthy not-influenced 2) healthy challenged by beta blocker 3) with stress-induced myocardial injuries 4) with stress-induced injuries challenged by beta-blocker. It is shown that cardiorespiratory synchronization plays an essential role at each of these stages.