US 5,318,594 A · DDD type cardiac pacemaker having automatic operating mode switching

Abstract

A cardiac pacemaker that is programmable to have one of a DDD and an AAI pacing mode of operation such that the pacing mode best suited to the patient's physiological condition is selected and implemented. The heart is paced in the AAI mode during periods of atrio-ventricular conduction. It automatically switches to pacing the heart in the DDD mode in response to a lack of atrio-ventricular conduction, and automatically switches back to the AAI mode after occurrence of a restoration event including restoration of atrio-ventricular conduction. Time delays for use in the DDD mode are calculated during operation in the AAI mode prior to loss of atrio-ventricular conduction and other timing delays for monitoring the patient's current physiological condition for mode switching are calculated.

Claims40

Dependent claims

In a cardiac pacemaker having a AAI mode of operation and a DDD mode of operation, a method of switching between modes of operation comprising:

monitoring atrial events including atrial detection and atrial pacing outside of a selected refractory period;
selecting a ventricular surveillance delay period following the occurrence of a sensed atrial event;
monitoring atrio-ventricular conduction following each sensed atrial event during the selected ventricular surveillance delay period;
and
operating the pacemaker in the DDD mode of operation if there is no sensed atrio-ventricular conduction during the ventricular surveillance delay period and operating the pacemaker in the AAI mode of operation if there is atrio-ventricular conduction during the ventricular surveillance delay period.

2 more elements

Dependencies are inferred from the claim text.

DDD type cardiac pacemaker having automatic operating mode switching

Life of this patent

DDD type cardiac pacemaker having automatic operating mode switching

Life of this patent

Abstract

Claims40