| 摘要 |
The cardiac pacer disclosed herein responds to a premature heartbeat by first digitally measuring the time interval between a pair of successive sensed heartbeats and establishing an escape interval for stimulation which is shorter than the measured heartbeat interval. Pacing at this shorter escape interval enables the pacer to capture and control the heartbeat rate. By repeatedly incrementing the digital value representing the escape value on successive stimulated heartbeats, the heart is then caused to slow down until a preselected desired rate is established. Preferably, the sensing and timing between heartbeats continues during the slowdown process so that, if, at any time, a natural heartbeat occurs earlier than the stimulation pulse at the then extant escape interval, the escape interval is reset to a shorter time so that capture will be re-established. |
