An access disconnection system includes a venous line, an arterial line, a first electrode coupled to (i) the arterial line, (ii) a patient, or (iii) a cardiac catheter assembly； and a second electrode coupled to (i) the venous line, or (ii) the cardiac catheter assembly. The access disconnection system further includes electronic circuitry communicating electrically with the first second electrode to sense an electrical heartbeat signal generated by the patient. The electronic circuitry is configured to send a disconnection output indicative of a change in the electrical signal sufficient to expect that an access disconnection of the venous line has occurred.
