| 摘要 |
A heart stimulator is described which is capable of sensing and stimulating both the atrium and the ventricle in a heart in such a way that a ventricular stimulation pulse is emitted, either after expiration of an atrioventricular interval (20a - d) following a stimulated or spontaneous atrial event (19a - e) or after expiration of a minimum synchronous interval (26a - d) following a stimulated or spontaneous ventricular event (24a - d), depending on which of the two intervals expires last. After each ventricular event (24a - d), an atrial refractory period (27a - d) is imposed during which atrial detections are interpreted as noise. Operation of the heart stimulator when the atrium's spontaneous rate is faster than a stimulation rate corresponding to the minimum synchronous interval is improved when the interval (21a - f) between atrial events (19a - 19e) is measured. If a detection (19d) during the atrium's refractory period (27c) occurs at a time corresponding to the latest interval timed (21c), the detection (19d) is interpreted as an approved atrial event, and a ventricular stimulation pulse (23d) is emitted after expiration of the minimum synchronous interval (26c). <IMAGE> |
