Multi-site ventricular pacing system measuring QRS duration
First Claim
1. A cardiac pacing system for delivering electrical stimulation to a heart, comprising:
- a timing circuit to measure at least one time interval, the at least one time interval being used to control delivery of the electrical stimulation by the cardiac pacing system;
a sensing circuit to measure duration of a QRS complex of the heart; and
a control circuit coupled to the timing circuit and the sensing circuit to adjust the length of the at least one time interval based on the measured duration of the QRS complex of the heart.
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Accused Products
Abstract
Bi-Ventricular or AV synchronous cardiac pacing systems that pace and sense in at least one atrial heart chamber and deliver ventricular pacing pulses to right ventricular (RV) and left ventricular (LV) sites separated by a V-V delay for treatment of heart failure are disclosed that optimize one or more of the AV delay and V-V delay to enhance left ventricular filling and cardiac output as a function of QRS duration.
A system and method for monitoring the QRS duration, processing such signals to provide data from which the onset or progression of heart failure is determined, and adjusting synchronous pacing delay parameters including SAV delay and/or PAV delay and/or V-V delay to enhance cardiac output as a function of QRS duration is provided. The SAV, PAV, and/or the V-V delays can be varied from the prevailing delays as a function of measured QRS duration so as to minimize the width of the QRS complex.
77 Citations
47 Claims
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1. A cardiac pacing system for delivering electrical stimulation to a heart, comprising:
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a timing circuit to measure at least one time interval, the at least one time interval being used to control delivery of the electrical stimulation by the cardiac pacing system;
a sensing circuit to measure duration of a QRS complex of the heart; and
a control circuit coupled to the timing circuit and the sensing circuit to adjust the length of the at least one time interval based on the measured duration of the QRS complex of the heart. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A multi-site, cardiac pacing system for pacing first and second ventricular sites of a patient'"'"'s heart comprising:
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means for timing out a pacing escape interval;
means for sensing ventricular depolarizations at a first ventricular site and providing a ventricular sense event signal;
means for delivering a first ventricular pacing pulse to the first ventricular site if the pacing escape interval times out before a ventricular sense event signal is provided;
V-V delay timing means for timing a V-V delay from the delivery of the first ventricular pacing pulse or a ventricular sense event;
means for delivering a second ventricular pacing pulse to the second ventricular site at the time-out of the V-V delay; and
means operable upon satisfaction of event criteria for determining the V-V delay that optimizes ventricular cardiac output further comprising;
QRS duration measuring means operable upon delivery of the second pacing pulse for measuring the QRS duration of the evoked depolarization of the heart;
efficacy determining means for determining the efficacy of the delivery of the first and second pacing pulses separated by the V-V delay ascertained from the measured QRS duration;
means for establishing the V-V delay timed out by the V-V delay timing means as the V-V delay found efficacious by the determining means. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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19. A method of operating a multi-site, cardiac pacing system for pacing first and second ventricular sites of a patient'"'"'s heart to determine pacing efficacy comprising the steps of:
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timing out a pacing escape interval;
sensing ventricular depolarizations at a first ventricular site and providing a ventricular sense event signal;
delivering a first ventricular pacing pulse to the first ventricular site if the pacing escape interval times out before a ventricular sense event signal is provided;
delivering a second ventricular pacing pulse to the second ventricular site at the time-out of the V-V delay; and
determining the V-V delay that optimizes ventricular cardiac output further comprising the steps of;
measuring the QRS duration of the evoked depolarization of the heart upon delivery of the second pacing pulse;
determining the efficacy of the delivery of the first and second pacing pulses separated by the V-V delay from the measured QRS duration;
establishing the V-V delay timed out in the timing step as the V-V delay found efficacious by the determining means.
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30. In a multi-site, AV sequential, cardiac pacing system wherein ventricular pacing pulses are delivered to the right and left ventricles synchronously within a V-V delay following time-out of an AV delay from a preceding delivered atrial pace pulse or an atrial sense event, in accordance with the steps of:
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(a) timing an AV delay from a preceding delivered atrial pace pulse or an atrial sense event;
(b) detecting a ventricular depolarization in one of the right and left ventricle within the AV delay and, in response, terminating the AV delay and providing a ventricular sense event;
(c) delivering a ventricular pace pulse to selected one of the right and left ventricle upon the time-out of the AV delay;
(d) timing the V-V delay from a ventricular sense event occurring prior to the time-out of the AV delay or from a ventricular pace pulse delivered at the end of the AV delay; and
(e) delivering a ventricular pace pulse to the other of the right and left ventricle upon the time-out of the V-V delay;
a method of periodically optimizing cardiac output achieved by the synchronous pacing of the right and left ventricles comprising the steps of;
(f) measuring the QRS duration of the evoked depolarization of the other of the right and left ventricle paced at the time-out of the V-V delay following step (e);
(g) adjusting the V-V delay;
(h) repeating steps (a) through (g) to derive a set of measured QRS duration values correlated with a set of V-V delays;
(i) determining the shortest QRS duration; and
(j) employing the V-V delay correlated with the shortest QRS duration in step (d) until steps (f) through (I) are repeated. - View Dependent Claims (31, 32, 33, 34, 35, 37, 38, 39, 40, 41)
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36. In a multi-site, AV sequential, cardiac pacing system wherein ventricular pacing pulses are delivered to the right and left ventricles synchronously within a V-V delay following time-out of an AV delay from a preceding delivered atrial pace pulse or an atrial sense event, comprising:
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(a) means for timing an AV delay from a preceding delivered atrial pace pulse or an atrial sense event;
(b) means for detecting a ventricular depolarization in one of the right and left ventricle within the AV delay and, in response, terminating the AV delay and providing a ventricular sense event;
(c) means for delivering a ventricular pace pulse to selected one of the right and left ventricle upon the time-out of the AV delay;
(d) means for timing the V-V delay from a ventricular sense event occurring prior to the time-out of the AV delay or from a ventricular pace pulse delivered at the end of the AV delay; and
(e) means for delivering a ventricular pace pulse to the other of the right and left ventricle upon the time-out of the V-V delay;
a system that periodically optimizes cardiac output achieved by the synchronous pacing of the right and left ventricles comprising the steps of;
means for measuring the QRS duration of the evoked depolarization of the other of the right and left ventricle paced at the time-out of the V-V delay;
(g) means for adjusting the V-V delay;
(h) means for repeating the operations of means (a) through (g) to derive a set of measured QRS duration values correlated with a set of V-V delays;
(i) means for determining the shortest QRS duration; and
(j) means for employing the V-V delay correlated with the shortest QRS duration in means (d) until the system is enabled to again optimize cardiac output.
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42. A method for use in a cardiac pacing system for optimizing delivery of electrical stimulation to a heart, comprising the methods of:
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(a) timing at least one time interval;
(b) delivering electrical stimulation to a first location in the heart at a predetermined time relative to the least one time interval;
(c) measuring duration of a QRS complex of the heart; and
(d) adjusting the length of the at least one time interval based on the measured duration of the QRS complex of the heart. - View Dependent Claims (43, 44, 45, 46, 47)
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Specification