Systems and methods for controlling a ventricular rate during atrial fibrillation are provided. In some aspects, a method includes selecting a treatment protocol based on a determined condition of a subject, the treatment protocol comprising intermittent periods of electrical stimulation separated by periods of non-stimulation. The method also includes applying an electrical stimulation, according to the selected the treatment protocol, using an electrical source and at least one electrode positioned at locations associated with a vagal nerve of the subject to control a ventricular rate during atrial fibrillation.
