Implantable pacemaker providing hysteresis in dual-chamber modes

摘要: An implantable pacemaker provides three types of hysteresis for use in dual chamber and/or atrial tracking modes, such as VDI, VDD, DDI, DDD, VDIR, VDDR, DDIR or DDDR. The defines a basic escape interval (AEI) that the maximum time between ventricular event and subsequent event, well an AV delay (AVD) next event. sum AEI plus AVD thus sets rate at which stimulation pulses are generated absence sensed natural cardiac activity. A first type hysteresis, causes to be extended upon sensing beats (P-waves). increased remains force so long P-waves continue during AEI. Should P-wave not AEI, pulse is reverts its initial value. second atrial-induced extends shortens response P-wave, thereby keeping pacemaker's programmed same. third ventricular-induced R-wave. Any desired combination may programmably selected within pacemaker.