Multi-site ventricular pacing system measuring QRS duration

• US 6,804,555 B2
• Filed: 06/29/2001
• Issued: 10/12/2004
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Warkentin, Dwight H.
• Primary Examiner(s): Schaetzle, Kennedy
• Assistant Examiner(s): Oropeza, Frances P.
• Application Number:
  US09/896,281
• Publication Number:
  US 20030004548A1
• Time in Patent Office: 1,201 Days
• Field of Search: 600/373, 600/374, 600/504, 600/516, 600/521, 607/4, 607/5, 607/9, 607/11, 607/14
• US Class Current: 607/9
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation

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.

Claims

1. A cardiac pacing system for delivering electrical stimulation to at least three chambers of a heart, said at least three chambers including a left ventricular chamber and a right ventricular chamber wherein the left ventricular chamber and the right ventricular chamber do not synchronously contract, comprising:

a timing circuit to measure at least one time interval, the at least one time interval operatively coupled to control delivery of an electrical stimulatIon therapy to at least one of a left ventricular chamber and a right ventricular chamber by a cardiac pacing system;

a sensing circuit to measure a duration of a ORS complex of only a last-to-depolarize ventricular chamber 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 last-to-depolarize ventricular chamber of the heart.

2. A system according to claim 1, wherein the sensing circuit includes a circuit to sense a depolarization in a selected one of the left or right atria of the heart, and wherein the at least one time interval further comprises an sensed A-V (SAV) delay initiated upon sensing of the depolarization, and further comprising:

an output circuit coupled to the timing circuit to;

a) deliver a first ventricular pacing pulse to a first ventricular site disposed in a first ventricular chamber upon expiration of the SAV delay and a second ventricular placing pulse to a second ventricular site disposed in a second ventricular chamber, wherein said second ventricular pacing pulse is delivered after a temporal interval following delivery of said first ventricular pacing pulse, or

b) upon detecting a ventricular depolarization in said first ventricular chamber prior to expiration of the SAV delays withholding delivery of the first ventricular pacing pulse and delivering the second ventricular pacing pulse after a temporal interval following detection of said ventricular depolarization, or

c) upon detecting a ventricular depolarization in said second ventricular chamber prior to expiration of the SAV delay, withholding delivery of the second ventricular acing pulse and delivering the first ventricular pacing pulse after a temporal interval following detection of said ventricular depolarization.

3. A system according to claim 2, wherein the output circuit includes a circuit to deliver an atrial pacing pulse to the selected one of the left or right atria of the heart upon expiration of a V-A escape interval, and wherein the at least one time interval includes a paced A-V (PAV) delay initiated upon delivery of the atrial pacing pulse, and wherein the output circuit further comprises a circuit to deliver the first ventricular pacing pulse to the first ventricular site upon expiration of the PAV delay.

4. A system according to claim 2, wherein the temporal interval comprises a bi-ventricular delay.

5. A system according to claim 4, wherein the first ventricular chamber is a location within the right ventricle of the heart and the second ventricular chamber is a location within the left ventricle of the heart.

6. A system according to claim 4, wherein the first ventricular chamber is a location within the left ventricle of the heart and the second ventricular chamber is a location within the right ventricle of the heart.

7. A system according to claim 4, wherein the output circuit includes a circuit to deliver a pacing pulse to the other one of the left or right atria of the heart.