In embodiments, an emergency external defibrillator system is configured for use by a local rescuer in cooperation with a remote rescuer to assist a patient. The external defibrillator system includes a sensor to generate a patient value that represents a physiological parameter of the patient. The system also includes a communication module to transmit the patient value to another device of a remote rescuer, and to receive in response an incoming message that contains an encoded discharge instruction. The system also includes a processor that can decode the discharge instruction, and cause the system to defibrillate or pace the patient. An advantage is that therapy can be initiated remotely from the remote rescuer, who may be better trained, more confident, and less under the stress of the moment than the local rescuer.