An eavesdropping arrangement for acquiring a measured physiological variable of an individual includes a receiver and a communication interface in a housing separate from the receiver. The communication interface is positioned along a communication link between a first sensor, which is configured to measure aortic blood pressure and to provide a signal representing measured aortic blood pressure, and a central monitoring device configured to monitor the measured aortic blood pressure. The communication interface includes a high impedance connection to the communication link that permits the communication interface to eavesdrop on the signal representing measured aortic blood pressure such that information representing measured aortic blood pressure is sent to the receiver while allowing the central monitoring device to receive and use the signal representing measured aortic blood pressure.