A vagus nerve neurostimulator system with multiple patient-selectable modes for treating chronic cardiac dysfunction is provided. An implantable neurostimulator includes a pulse generator coupled to a therapy lead terminated by a pair of helical electrodes positioned over a cervical vagus nerve. The pulse generator is configured to deliver through the helical electrodes continuously-cycling, intermittent and periodic electrical stimulation that is parametrically defined to bi-directionally propagate through nerve fibers in the cervical vagus nerve. The implantable neurostimulator includes a magnetic switch configured to switch the pulse generator between a plurality of operating modes that are each separately selectable in response to a unique and remotely-applied magnetic signal. An external controller includes patient-actuatable controls configured to enable selection of one of the operating modes of the pulse generator. The external controller includes an electromagnetic transmitter configured to output the magnetic signal uniquely associated with the operating mode as selected with the controls.