An implantable, microprocessor-based cardiac pacer provides physiologically adaptive pacing in four fundamental modes: ventricular-inhibited; atrial-synchronized ventricular with or without ventricular sensing; and atrial-ventricular (AV) sequential. In the AV sequential mode, the pacer automatically...http://www.google.co.uk/patents/US4485818?utm_source=gb-gplus-sharePatent US4485818 - Multi-mode microprocessor-based programmable cardiac pacer
