| 摘要 |
A system for determining P-wave or R-wave capture in response to pacemaker supplied electrical stimuli. One embodiment includes a conventional bipolar atrial lead having a tip electrode, connected to an atrial pulse generator circuit within an implantable pacemaker, and a ring electrode, spaced apart from the tip electrode, connected to a P-wave sensing EGM amplifier within the pacemaker. The bandpass characteristics of the P-wave sensing EGM amplifier allow detection of all electrical frequencies in the atrium within the bandpass chosen. The output signal from this amplifier is selectively telemetered to an external receiver, as is a signal indicating the generation of an atrial stimulation pulse, where the occurrence of atrial stimulation pulses and P-waves can be monitored. In operation, if constant time intervals between the monitored atrial stimulation pulses and P-wave occurrences are present, P-wave capture has occurred. In the event of variable time intervals, capture has not occurred and the magnitude of the atrial stimulation pulses can be increased until P-wave capture does occur. An alternative embodiment measures this time differential and makes the stimulation pulse adjustment automatically. Other embodiments use the same manual or automatic systems to determin R-wave capture.
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