Implanatable cardiac stimulation device and method for prolonging atrial refractoriness

A method of pacing a patient's heart, the method comprising the steps of:

• determining a primary atrial event;
• timing a delay time period following the primary atrial event;
• and
• delivering a secondary atrial pacing pulse to an atrium of the patient's heart at the end of the delay time period, whereby the refractory period of the atrium is prolonged.

An implantable cardiac stimulation device for stimulating a patient's heart through a first electrode in electrical communication with an atrium of the patient's heart, the implantable stimulation device comprising:

• sensing circuitry that senses cardiac activity;
• a pulse generator adapted to be electrically coupled to the electrode and that is operative to generate pacing pulses for delivery to the atrium via the electrode;
• and
• a controller that is coupled to the sensing circuitry and the pulse generator, wherein the controller is operative to receive sense signals from the sensing circuitry and to cause the pulse generator to deliver a secondary pacing pulse to the atrium at least about 120 milliseconds after a primary atrial event.