An implantable device includes a posture sensor and a physiological signal sensor. The posture sensor supplies at least one first sensor output signal indicating body posture and/or changes therein. The physiological signal sensor supplies at least one second sensor output signal indicative of at least one physiological parameter such as blood pressure, intracardiac impedance, stroke volume, heart sounds, heart rate, and/or biochemical measurements (e.g., oxygen concentration). An evaluation unit processes the first and second sensor output signals and determines one or more variables that describe the dynamic behavior of the second sensor output signal in response to a change in body posture indicated by the first sensor output signal.
