A method for adjusting a pacing rate in a dual-chamber, leadless pacemaker implanted in a heart may involve determining, with a leadless atrial pacemaker implanted in an atrium of the heart, that an intrinsic atrial contraction rate of the atrium is faster than a ventricular contraction rate, transmitting a first signal from the atrial pacemaker to a leadless ventricular pacemaker implanted in a ventricle of the heart to increase a ventricular pacing rate of the ventricular pacemaker, receiving the transmitted first signal with the ventricular pacemaker, and increasing the ventricular pacing rate, based on the received first signal.
