Template based AV/VA interval comparison for the discrimination of cardiac arrhythmias
First Claim
1. A system for discriminating ventricular tachycardia (VT) from supraventricular tachycardia (SVT), the system comprising:
- a sensing circuit that senses an atrial electrogram indicative of atrial depolarizations and a ventricular electrogram indicative of ventricular depolarizations;
a rate detector circuit, coupled to the sensing circuit, that detects an atrial rate based on the atrial electrogram and a ventricular rate based on the ventricular electrogram;
a tachycardia detector circuit, coupled to the rate detector circuit, that detects a tachycardia based on at least one of the atrial rate and the ventricular rate;
a rhythm classifier circuit, coupled to the rate detector circuit and the tachycardia detector circuit, that classifies the detected tachycardia as a 1;
1 tachycardia in response to the atrial rate and the ventricular rate being substantially equal; and
a tachycardia discriminator circuit coupled to the rhythm classifier circuit, the tachycardia discriminator circuit including;
a time interval measurement circuit, coupled to the sensing circuit, that measures a tachycardia time interval between an atrial depolarization and an adjacent ventricular depolarization during the 1;
1 tachycardia; and
a VT comparator circuit coupled to the time interval measurement circuit, the VT comparator circuit having an output that indicates a VT detection in response to the VT comparator circuit determining that the tachycardia time interval differs from a template time interval by at least a predetermined percentage of the template time interval and that indicates a detection of SVT in response to the VT comparator circuit determining that the tachycardia time interval does not differ from the template time interval by at least the predetermined percentage of the template time interval,wherein the template time interval is a time interval between an atrial depolarization and an adjacent ventricular depolarization measured during a normal sinus rhythm.
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Accused Products
Abstract
An implantable cardioverter/defibrillator includes a tachycardia detection system that detects one-to-one (1:1) tachycardia, which is a tachycardia with a one-to-one relationship between atrial and ventricular contractions. When the 1:1 tachycardia is detected, the system discriminates ventricular tachycardia (VT) from supraventricular tachycardia (SVT) based on analysis of a cardiac time interval. Examples of the cardiac time interval include an atrioventricular interval (AVI) and a ventriculoatrial interval (VAI). A template time interval is created during a known normal sinus rhythm. The system measures a tachycardia time interval after detecting the 1:1 tachycardia, and indicates a VT detection if the tachycardia time interval differs from the template time interval by at least a predetermined percentage of the template time interval.
210 Citations
42 Claims
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1. A system for discriminating ventricular tachycardia (VT) from supraventricular tachycardia (SVT), the system comprising:
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a sensing circuit that senses an atrial electrogram indicative of atrial depolarizations and a ventricular electrogram indicative of ventricular depolarizations; a rate detector circuit, coupled to the sensing circuit, that detects an atrial rate based on the atrial electrogram and a ventricular rate based on the ventricular electrogram; a tachycardia detector circuit, coupled to the rate detector circuit, that detects a tachycardia based on at least one of the atrial rate and the ventricular rate; a rhythm classifier circuit, coupled to the rate detector circuit and the tachycardia detector circuit, that classifies the detected tachycardia as a 1;
1 tachycardia in response to the atrial rate and the ventricular rate being substantially equal; anda tachycardia discriminator circuit coupled to the rhythm classifier circuit, the tachycardia discriminator circuit including; a time interval measurement circuit, coupled to the sensing circuit, that measures a tachycardia time interval between an atrial depolarization and an adjacent ventricular depolarization during the 1;
1 tachycardia; anda VT comparator circuit coupled to the time interval measurement circuit, the VT comparator circuit having an output that indicates a VT detection in response to the VT comparator circuit determining that the tachycardia time interval differs from a template time interval by at least a predetermined percentage of the template time interval and that indicates a detection of SVT in response to the VT comparator circuit determining that the tachycardia time interval does not differ from the template time interval by at least the predetermined percentage of the template time interval, wherein the template time interval is a time interval between an atrial depolarization and an adjacent ventricular depolarization measured during a normal sinus rhythm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A cardiac rhythm management (CRM) system, comprising:
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an implantable atrial lead allowing for sensing an atrial electrogram indicative of atrial depolarizations; an implantable ventricular lead allowing for sensing a ventricular electrogram indicative of ventricular depolarizations; and an implantable cardioverter/defibrillator (ICD) including; a sensing circuit, coupled to the implantable atrial lead and the implantable ventricular lead, to sense the atrial electrogram and the ventricular electrogram; a rate detector circuit, coupled to the sensing circuit, that detects an atrial rate based on the atrial electrogram and a ventricular rate based on the ventricular electrogram; a tachycardia detector circuit, coupled to the rate detector circuit, that detects a tachycardia based on at least one of the atrial rate and the ventricular rate; a rhythm classifier circuit, coupled to the rate detector circuit and the tachycardia detector circuit, that classifies the detected tachycardia as a 1;
1 tachycardia in response to the atrial rate and the ventricular rate being substantially equal; anda tachycardia discriminator circuit coupled to the rhythm classifier circuit, the tachycardia discriminator circuit including; a time interval measurement circuit, coupled to the sensing circuit, that measures a tachycardia time interval between an atrial depolarization and an adjacent ventricular depolarization during the 1;
1 tachycardia; anda VT comparator circuit coupled to the time interval measurement circuit, the VT comparator circuit having an output that indicates a detection of VT in response to the VT comparator circuit determining that the tachycardia time interval differs from a template time interval by at least a predetermined percentage of the template time interval and that indicates an SVT detection in response to the VT comparator circuit determining that the tachycardia time interval does not differ from the template time interval by at least the predetermined percentage of the template time interval, wherein the template time interval is a time interval between an atrial depolarization and an adjacent ventricular depolarization measured during a normal sinus rhythm. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method for discriminating ventricular tachycardia (VT) from supraventricular tachycardia (SVT), the method comprising:
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detecting a ventricular rate being a frequency of ventricular depolarizations; detecting an atrial rate being a frequency of atrial depolarizations; detecting a tachycardia based on at least one of the atrial and ventricular rates; classifying the tachycardia as a 1;
1 tachycardia if the detected atrial rate is substantially the same as the detected ventricular rate;measuring a tachycardia time interval between adjacent atrial and ventricular depolarizations during the 1;
1 tachycardia;determining whether the tachycardia time interval differs from a template time interval by at least a predetermined percentage of the template time interval; indicating a VT detection if the determining indicates that the tachycardia time interval differs from the template time interval by at least the predetermined percentage of the template time interval; and indicating a SVT detection if the determining indicates that the tachycardia time interval does not differ from the template time interval by the predetermined percentage of the template time interval, wherein the template time interval is a time interval between adjacent atrial and ventricular depolarizations measured during a normal sinus rhythm. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42)
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Specification