1. A system, comprising: a sensing input configured to sense a tachyarrhythmia; a rhythm sensor coupled to the sensing input, the rhythm sensor configured to: compare a sensed tachyarrhythmia with a ventricular tachyarrhythmia criterion; and compare a sustained tachyarrhythmia with a supraventricular tachyarrhythmia (SVT) criterion when the tachyarrhythmia continues during or after a neural stimulation; a ventricular tachyarrhythmia therapy generator, coupled to the rhythm sensor, configured to: provide a ventricular tachyarrhythmia therapy when the sensed tachyarrhythmia satisfies the ventricular tachyarrhythmia criterion; and provide a ventricular tachyarrhythmia therapy when the sensed tachyarrhythmia does not satisfy the SVT criterion; and a neural stimulation generator, coupled to the rhythm sensor, configured to provide a neural stimulation when the sensed tachyarrhythmia does not satisfy the ventricular tachyarrhythmia criterion.