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ATRIAL THRESHOLD TESTING WITH VENTRICULAR BACKUP IN NON-SYNCHRONIZED PACING MODE

IP.com Disclosure Number: IPCOM000085653D
Publication Date: 2005-Mar-02
Document File: 3 page(s) / 81K

Publishing Venue

The IP.com Prior Art Database

Abstract

This disclosure describes a process that enables evaluation of atrial capture for consecutive beats while maintaining lower rate ventricular support. Such an improvement can be implemented relatively easily into cardiac rhythm management devices including pacemakers, implantable cardioverters/defibrillators, cardiac resynchronizers, and other such devices.

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ATRIAL THRESHOLD TESTING WITH VENTRICULAR BACKUP

IN NON-SYNCHRONIZED PACING MODE

           

            Conventional modes for atrial threshold testing include AAI mode “overdrive pacing” if the AV node is intact, and DDD mode with extended AV delay (300 msec.) for AV block patients.  The AAI mode is problematic for patients with atrial arrhythmias, high degree of heart blockage or ablated AV node.  In the DDD mode with ventricular pacing, even at extended AV delay, confusion may arise because a P-wave can be lost in the ventricular complex.  This makes atrial threshold testing difficult for pacemaker dependent patients. 

            This disclosure describes a process that enables evaluation of atrial capture for consecutive beats while maintaining lower rate ventricular support.  Such an improvement can be implemented relatively easily into cardiac rhythm management devices including pacemakers, implantable cardioverters/defibrillators, cardiac resynchronizers, and other such devices. 

            In accordance with one example, this atrial threshold measurement technique utilizes asynchronous atrial pacing at a rate above the sinus rhythm to determine the atrial capture threshold while minimizing the interference from the native ventricular rhythm.  Atrial capture or loss of capture can be evaluated through the presence or absence of a P-wave.

            In one example of this process, asynchronous pacing is performed with AAI and VVI pacing at a different rate, e.g., AAI pacing at a rate of 90 ppm, or higher than the patient’s intrinsic sinus rate at the time of testing, along with backup VVI pacing at a rate of 50 ppm.  The atrial pacing output automatically steps-down after a programmable number of pulses, e.g., every 3 pulses.  This automatic step-down can be fixed or programmable. 

            The process may be initiated through the use of a device programmer having a Diagnostic Evaluation/ Threshold Test screen with additional selection buttons (Atrium and Asynch) for chamber test selection.  Two additional selection windows may be utilized to allow the clinician to enter an independent atrial test rate and a ventricular backup rate when the Atrium, Asynch buttons are selected.  Similarly, when the Atrium, Asynch buttons are selected, a parameter input window can popup for input of additional parameter...