Copyright © Philip M. Parker, INSEAD. Terms of Use.
| Year | Description |
| 1996 | Invention patented by Jason A. Sholder on May 6th, 1996. Abstract: A DDI pacemaker detects when a pacemaker mediated retrograde rhythm (PMRR) occurs, and automatically alters the DDI operation to terminate the PMRR. The PMRR is detected by measuring the P-to-V time interval in a DDI pacing cycle that terminates in the generation of a ventricular stimulation pulse (V-pulse). A PMRR is presumed to be present whenever the measured P-to-V interval exceeds a prescribed time interval, or whenever a programmed number of consecutive P-to-V time intervals, e.g., ten, are greater than the prescribed time interval. Once a PMRR is detected, the pacemaker automatically extends the post-ventricular atrial refractory period (PVARP) of the pacemaker to block any retrograde P-waves that may be occurring as part of the PMRR. As soon as the extended PVARP terminates, an alert time interval, T.sub.ALERT, begins that is selected to be of sufficient length to allow atrial tissue to repolarize and/or to detect a normal P-wave. If a P-wave is not sensed during the T.sub.ALERT interval, which will normally be the case in the presence of a PMRR, an atrial stimulation pulse (A-pulse) is generated that effectively prevents the next ventricular event from triggering a retrograde P-wave, thereby terminating the PMRR. |
| Source: selected by the editor from original sources. | |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
