The aim of this study was to detect pathological changes of the complex autonomous regulation of ecg, blood pressure and respiration (synchronously recordings of 30 minutes) in patients with cardiac diseases. We investigated the cardiovascular and cardiorespiratory linear and nonlinear interactions in 10 patients with dilative cardiomyopathy (dcm) and in 10 patients after myocardial infarction (mi). We compared results from the classical linear correlation function analysis with results from the mutual information method (transinformation) for analysis of nonlinear and linear interactions. Both methods yield high significant parameters (p < 0.01). Thus, we found both linear and nonlinear interactions with partly different specificity in patients with dcm and mi compared to healthy subjects (ref).