Method and apparatus for optimizing cardiac pumping performance

• US 7,206,634 B2
• Filed: 07/26/2002
• Issued: 04/17/2007
• Est. Priority Date: 07/26/2002
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Yu, Yinghong, Zhu, Qingsheng, Ding, Jiang
• Primary Examiner(s): Pezzuto; Robert
• Assistant Examiner(s): JOHNSON, SHEVON ELIZABETH
• Application Number:
  US10/206,131
• Publication Number:
  US 20040019365A1
• Time in Patent Office: 1,726 Days
• Field of Search: 607/9, 607/4, 607/25, 607/17
• US Class Current: 607/17
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• 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 1/36842 Multi-site stimulation in the same chamber
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation

Abstract

A cardiac rhythm and function management device configured to automatically adjust stimulation parameters used in delivering cardiac resynchronization therapy. Mechanical contraction intervals are measured using appropriately placed accelerometers and compared with optimum values. The stimulation parameters can then be adjusted accordingly in a manner that moves the mechanical contraction intervals toward their optimum values.

Claims

1. A cardiac device, comprising:

an atrial sensing channel;

a first stimulation channel configurable for stimulating the right or left ventricle;

a controller for controlling the delivery of stimulus pulses through the stimulation channels in accordance with a programmed mode, wherein the controller is programmed to stimulate the right or left ventricle in an atrial tracking mode with a specified atrio-ventricular interval between an atrial sense and a ventricular stimulus;

a left atrial accelerometer adapted for contacting a wall of the left atrium in order to sense mechanical contraction of the left atrium;

a left ventricular accelerometer configurable for sensing mechanical contraction of the left ventricle;

wherein the controller is programmed to measure the time interval between sensed mechanical contractions of the left atrium and the left ventricle as sensed by the accelerometers during a cardiac cycle; and

,

wherein the controller is further programmed to adjust the atrio-ventricular interval until the measured time interval between contractions of the left atrium and left ventricle equals a specified value (T1).

2. The device of claim 1 further comprising:

a ventricular sensing channel;

a right ventricular accelerometer configurable for sensing contraction of the right ventricle; and

,

wherein the controller is programmed to stimulate one ventricle at a biventricular offset interval with respect to a sense from the contralateral ventricle, and further wherein the controller is programmed to adjust the biventricular offset interval until the measured interval between contractions of the right and left ventricles equals a specified value (T2).

3. The device of claim 2 further comprising a second stimulation channel configurable for stimulating the right or left ventricle and wherein the controller is programmed to stimulate one ventricle at the biventricular offset interval with respect to either a sense or stimulation of the contralateral ventricle, and further wherein the controller is programmed to adjust the biventricular offset interval until the measured interval between contractions of the right and left ventricles equals a specified value (T2).

4. The device of claim 2 wherein the specified value (T2) is approximately zero.

5. The device of claim 2 wherein the biventricular offset interval may be positive, negative, or zero.

6. The device of claim 1 further comprising:

a second stimulation channel configurable for stimulating the right or left ventricle;

a right ventricular accelerometer configurable for sensing contraction of the right ventricle; and

,

wherein the controller is programmed to stimulate one ventricle at a biventricular offset interval with respect to stimulation of the contralateral ventricle, and further wherein controller is programmed to adjust the biventricular offset interval until the measured interval between contractions of the right and left ventricles equals a specified value (T2).

7. The device of claim 6 wherein the specified value (T2) is approximately zero.

8. The device of claim 6 wherein the biventricular offset interval may be positive, negative, or zero.

9. The device of claim 1 further comprising an atrial stimulation channel and wherein the controller is programmed to pace an atrium such that an atrial stimulus and a ventricular stimulus are separated by the specified atrio-ventricular interval.

10. A method for operating a cardiac device, comprising:

sensing electrical activity in an atrium;

delivering stimulus pulses to the right or left ventricle in an atrial tracking mode with a specified atrio-ventricular interval between an atrial sense and a ventricular stimulus;

sensing mechanical contraction of the left ventricular free wall;

sensing mechanical contraction of the left atrium;

measuring the time interval between sensed mechanical contractions of the left atrium and the left ventricle during a cardiac cycle; and

,

adjusting the atrio-ventricular interval until the measured time interval between contractions of the left atrium and left ventricle equals a specified value (T1).

11. The method of claim 10 further comprising:

sensing mechanical contraction of the right ventricle;

sensing electrical activity in at least one of the right and left ventricles;

stimulating one ventricle at a biventricular offset interval with respect to a sense from the contralateral ventricle; and

,

adjusting the biventricular offset interval until the measured interval between contractions of the right and left ventricles equals a specified value (T2).

12. The method of claim 11 further comprising stimulating both right and left ventricles, wherein one ventricle is stimulated at the biventricular offset interval with respect to either a sense or stimulation of the contralateral ventricle.

13. The method of claim 11 wherein the specified value (T2) is approximately zero.

14. The method of claim 11 wherein the biventricular offset interval may be positive, negative, or zero.

15. The method of claim 10 further comprising:

stimulating both right and left ventricles, wherein one ventricle is stimulated at a biventricular offset interval with respect to stimulation of the contralateral ventricle;

sensing mechanical contraction of the right ventricle; and

,

adjusting the biventricular offset interval until the measured interval between contractions of the right and left ventricles equals a specified value (T2).

16. The method of claim 15 wherein the specified value (T2) is approximately zero.

17. The method of claim 15 wherein the biventricular offset interval may be positive, negative, or zero.

18. The method of claim 10 further comprising pacing an atrium such that an atrial stimulus and a ventricular stimulus are separated by the specified atrio-ventricular interval.