Patent ID: 6757562
Filing Date: 2004-06-29
Classification: A61N

Abstract:
A cardiac rhythm management device, comprising:sensing channels for sensing depolarizations from heart chambers designated as a rate chamber and a synchronized chamber; a controller for controlling the delivery of paces in accordance with a programmed pacing mode; wherein the controller is programmed to: detect a tachyarrhythmia when a time interval between successive rate chamber senses is below a specified tachyarrhythmia rate threshold interval; pace the synchronized and rate chambers with a negative offset such that the rate chamber is paced upon expiration of an escape interval and a preceding pace is delivered to the synchronized chamber at a pacing instant defined by a negative offset interval, wherein the escape interval is reset by a rate chamber pace or a rate chamber sense and wherein a pacing interval, defined as the interval between a rate chamber pace or sense and expiration of an escape interval, is constrained by a specified maximum pacing rate to be no shorter than the specified tachyarrhythmia rate threshold interval; render the rate chamber sensing channel refractory for a selected cross-chamber sensing refractory period upon delivery of a synchronized chamber pace during which no sensing of rate chamber events occurs; and, inhibit a synchronized chamber pace at the pacing instant defined by the negative offset interval and deliver a pace to at least one of the chambers upon expiration of the escape interval when a maximum tachyarrhythmia rate threshold interval, defined as the pacing interval minus the negative offset interval, is less than a specified limit value.