Rate-responsive pacemaker with automatic mode switching and/or variable hysteresis rate
US4856523A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1987 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | Oct 8, 2007 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/36514
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
In a first embodiment, hysteresis is provided in a rate-responsive pacemaker to allow for natural AV synchrony when possible. In the absence of natural SA node signals, the heart is stimulated at a rate determined by the sensing of physiological need. When a natural heart signal is detected, the hysteresis is activated to extend the escape interval by a predetermined amount which is related to the sensed physiological need. The stimulating pulses are inhibited as long as normal heart activity is sensed. The extension of the escape interval under such conditions eliminates possible competition between normal activity and the paced stimulation. In a second embodiment automatic mode switching is provided in a dual chamber pacemaker to allow for more efficient operation at higher heart rates. When the heart rate (natural or paced) exceeds a prescribed level, such as 90 beats per minute, the pacemaker operates in a single chamber mode, such as VVI.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.