A method and device for delivering cardiac stimulation that includes a first electrode, positioned within a first chamber of a heart, sensing cardiac signals associated with the first chamber and capable of delivering stimulation to the first chamber, and a second electrode, positioned within a second chamber of the heart, sensing cardiac signals associated with the second chamber and capable of delivering stimulation to the second chamber. A processing unit processes the sensed signals and controls the stimulation delivery via the first electrode and the second electrode, determining whether a predetermined rhythm is detected in the first chamber, and delivering high-frequency burst pacing to the first chamber in response to a predetermined rate being sensed in the second chamber during the predetermined rhythm.