BACKGROUND: We investigated the relationship of impaired autonomic function and severity of illness in chronic heart failure (CHF) and multiple-organ dysfunction syndrome (MODS) as an end stage of CHF. Furthermore, we assessed the link of parasympathetic modulation of the heart rate and inflammatory activation in CHF and MODS. METHODS: Sixty-five patients admitted for worsening of CHF were retrospectively enrolled in this study. In addition, 65 age- and sex-matched patients with pronounced MODS were assigned for comparison of autonomic function and C-reactive protein in patients with CHF or MODS, respectively. Heart rate variability (HRV) parameters of the time and frequency domain as markers of autonomic function were analyzed from 24-hour Holter electrocardiograms. RESULTS: The more pronounced the severity of illness as expressed by the Acute Physiology and Chronic Health Evaluation score, the more the HRV was impaired. This effect was particularly seen for overall variability (SD of RR intervals) and HRV parameters characterizing the parasympathetic modulations of the heart rate (high, very low frequency power). C-reactive protein levels as markers of inflammation were inversely related to high and very low frequencies. CONCLUSION: Our results allow for speculation that autonomic dysfunction in CHF indicates a beginning of uncoupled interorgan communication potentially leading to MODS as characterized by disruption of communication between the organs.