A system for real-time assessment of vagus nerve stimulation for congestive heart failure treatment, the system comprising: a display; a vagus nerve stimulation, VNS, device configured to deliver a vagus nerve stimulation signal for congestive heart failure treatment, the stimulation signal having an ON-period status in which a stimulus is being delivered to a subject and an OFF-period status in which no stimulus is being delivered to the subject; a processor and a non-transitory computer readable memory storing instructions that, when executed by the processor, cause the system to: synchronously record a first ECG profile of the subject during the ON-period status of the VNS device and synchronously record a second ECG profile of the subject during the OFF-period status of the VNS device; determine real-time heart rate dynamics from the first and second ECG profiles, the real-time heart rate dynamics including a plurality of R-R intervals in each ECG profile; generate display data, configured to be displayed on the display, comprising the R-R intervals for each of the first and second ECG profiles to indicate real-time heart rate variability and real-time autonomic engagement, shown by a change in the real-time heart rate variability, in response to the vagus nerve stimulation signal during the ON-period status and OFF-period status of the VNS device, wherein the display data includes the R-R intervals in a dynamic, real-time Poincaré plot; and transmit the display data to the display. a display; a vagus nerve stimulation, VNS, device configured to deliver a vagus nerve stimulation signal for congestive heart failure treatment, the stimulation signal having an ON-period status in which a stimulus is being delivered to a subject and an OFF-period status in which no stimulus is being delivered to the subject; a processor and a non-transitory computer readable memory storing instructions that, when executed by the processor, cause the system to: synchronously record a first ECG profile of the subject during the ON-period status of the VNS device and synchronously record a second ECG profile of the subject during the OFF-period status of the VNS device; determine real-time heart rate dynamics from the first and second ECG profiles, the real-time heart rate dynamics including a plurality of R-R intervals in each ECG profile; generate display data, configured to be displayed on the display, comprising the R-R intervals for each of the first and second ECG profiles to indicate real-time heart rate variability and real-time autonomic engagement, shown by a change in the real-time heart rate variability, in response to the vagus nerve stimulation signal during the ON-period status and OFF-period status of the VNS device, wherein the display data includes the R-R intervals in a dynamic, real-time Poincaré plot; and transmit the display data to the display. synchronously record a first ECG profile of the subject during the ON-period status of the VNS device and synchronously record a second ECG profile of the subject during the OFF-period status of the VNS device; determine real-time heart rate dynamics from the first and second ECG profiles, the real-time heart rate dynamics including a plurality of R-R intervals in each ECG profile; generate display data, configured to be displayed on the display, comprising the R-R intervals for each of the first and second ECG profiles to indicate real-time heart rate variability and real-time autonomic engagement, shown by a change in the real-time heart rate variability, in response to the vagus nerve stimulation signal during the ON-period status and OFF-period status of the VNS device, wherein the display data includes the R-R intervals in a dynamic, real-time Poincaré plot; and transmit the display data to the display.