Dynamic cardiac resynchronization therapy by tracking intrinsic conduction

• US 8,725,257 B2
• Filed: 11/27/2012
• Issued: 05/13/2014
• Est. Priority Date: 10/06/2008
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Maskara, Barun, Ding, Jiang
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): Edwards, Philip
• Application Number:
  US13/686,352
• Publication Number:
  US 20130085539A1
• Time in Patent Office: 532 Days
• Field of Search: 607/9
• 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 1/36507 controlled by gradient or slope of the heart potential
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• 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

Systems and methods for pacing the heart using resynchronization pacing delays that achieve improvement of cardiac function are described. An early activation pacing interval is calculated based on an optimal AV delay and an atrial to early ventricular activation interval between an atrial event and early activation of a ventricular depolarization. The early activation pacing interval for the ventricle is calculated by subtracting the measured AV_EA from the calculated optimal AV delay. The early activation pacing interval is initiated responsive to sensing early activation of the ventricle and pacing is delivered relative to expiration of the early activation pacing interval.

Claims

1. A method of operating a cardiac pacing device, comprising:

measuring an atrial (A-A) interval and an intrinsic atrioventricular interval (AVI) of a first cardiac cycle;

calculating a pacing escape interval for a synchronized ventricular chamber based on the measured A-A interval and the measured AVI;

starting the pacing escape interval in response to sensing an intrinsic ventricular rate chamber depolarization of the first cardiac cycle;

during a second cardiac cycle immediately following the first cardiac cycle, pacing a ventricular synchronized chamber relative to expiration of the pacing escape interval; and

for each subsequent cardiac cycle, recalculating the pacing escape interval based at least on a measured A-A interval from an immediately previous cardiac cycle.

2. The method of claim 1, wherein the rate chamber is a right ventricle and the synchronized chamber is a left ventricle.

3. The method of claim 1, wherein the rate chamber is a left ventricle and the synchronized chamber is a right ventricle.

4. The method of claim 1, wherein calculating the pacing escape interval is based on calculating a difference between the intrinsic atrioventricular interval of the first cardiac cycle and an optimized synchronized chamber atrioventricular delay.

5. The method of claim 1, wherein calculating the pacing escape interval comprises calculating a difference between an intrinsic atrioventricular interval of the first cardiac cycle and an optimized synchronized chamber atrioventricular delay subtracted from the A-A interval of the first cardiac cycle.

6. A method of operating a cardiac rhythm management device, comprising:

electrically coupling electrodes to multiple chambers of a heart;

sensing cardiac electrical signals via the electrodes and detecting cardiac signal features associated with cardiac events;

measuring one or more cardiac intervals, including intervals between atrial events and atrioventricular intervals (AVIs) between an atrial event and a ventricular depolarization;

calculating a pacing escape interval for a synchronized ventricular chamber based on a measured A-A interval and a measured AVI for a first cardiac cycle;

starting the pacing escape interval in response to sensing an intrinsic ventricular rate chamber depolarization of the first cardiac cycle;

pacing a ventricular synchronized chamber relative to expiration of the pacing escape interval during a second cardiac cycle immediately following the first cardiac cycle; and

recalculating the pacing escape interval for each subsequent cardiac cycle based at least on a measured A-A interval of an immediately previous cardiac cycle.

7. The method of claim 6, wherein pacing the ventricular synchronized chamber comprises delivering right and left ventricular paces substantially simultaneously.

8. The method of claim 6, wherein pacing the ventricular synchronized chamber comprises sequentially delivering right and left ventricular paces separated by an interventricular delay.