Systems and methods for using pulmonary artery pressure from an implantable sensor to detect mitral regurgitation and optimize pacing delays

• US 9,566,442 B2
• Filed: 11/19/2012
• Issued: 02/14/2017
• Est. Priority Date: 11/19/2012
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Ngo, Thao, Kresge, Kathleen, Kane, Michael, Simon, Scott Patrick
• Primary Examiner(s): Berhanu, Etsub
• Application Number:
  US13/681,273
• Publication Number:
  US 20140142444A1
• Time in Patent Office: 1,548 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/02152 specially adapted for venous pressure
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• 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 1/36564 controlled by blood pressure
• 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

Abstract

Techniques are provided for use with a pulmonary artery pressure (PAP) monitor having an implantable PAP sensor. In one example, a PAP signal is sensed that is representative of beat-by-beat variations in PAP occurring during individual cardiac cycles of the patient. The PAP monitor detects peaks within the PAP signal corresponding to valvular regurgitation within the heart, then detects mitral regurgitation (MR) based on the peaks. In other examples, the PAP monitor optimizes pacing parameters based on the PAP signal and corresponding electrical cardiac signals. Examples are provided where the PAP monitor is an external system and other examples are provided where the PAP monitor is a component of an implantable cardiac rhythm management device.

Claims

1. A method for use with an implantable pulmonary artery pressure sensor and an implantable cardiac rhythm management device (CRMD) for implant within a patient, the method comprising:

sensing a pulmonary artery pressure (PAP) signal representative of variations in PAP occurring during individual cardiac cycles within the patient;

detecting a rate of change of the PAP signal with time (dPAP/dt);

detecting a maximum in the dPAP/dt signal (dPAP/dt|max) and a minimum in the dPAP/dt signal (dPAP/dt|min) within a portion of the PAP signal corresponding to an individual cardiac cycle; and

examining the dPAP/dt signal within a window between dPAP/dt|max and dPAP/dt|min to detect regurgitation peaks, if present, within the PAP signal;

detecting mitral regurgitation (MR) based on the presence of a regurgitation peak in the PAP signal;

detecting a pulmonary artery systole (PAS) peak within the PAP signal corresponding to a cardiac cycle;

detecting a delay interval between the PAS peak and the regurgitation peak; and

adjusting a cardiac pacing parameter based, at least in part, on the delay interval.

2. The method of claim 1 wherein detecting MR in the patient based on presence of regurgitation peaks in the PAP signal includes generating an indication of MR if MR peaks are detected in the PAP signal.

3. The method of claim 2 further including detecting progression of MR in the patient based on changes, if any, in the MR peaks over time.

4. The method of claim 1 wherein adjusting a cardiac pacing parameter includes adjusting an atrioventricular (AV) pacing delay.

5. The method of claim 4 wherein adjusting a cardiac pacing parameters additionally includes adjusting an interventricular (VV) pacing delay.

6. The method of claim 5 including performing further adjustments to pacing parameters based a hemodynamic optimization during a period of time when a pulmonary vascular resistance (PVR) value is substantially constant within the patient.

7. The method of claim 6 wherein the hemodynamic optimization includes:

estimating a value proportional to cardiac output (CO) from the PAP signal while PVR is substantially constant within the patient; and

adjusting a pacing parameter to improve CO.

8. The method of claim 7 wherein adjusting a pacing parameter to improve CO includes:

determining maximum values for PAP (maxPAP) within the PAP signal corresponding to a plurality of cardiac cycles;

determining a mean of the maxPAP values (maxPAP|mean);

determining a pulmonary artery diastole (PAD) pressure within a portion of the PAP signal corresponding to a current cardiac cycle;

determining a difference between maxPAP|mean and PAD pressure and comparing the difference between maxPAP|mean and PAD pressure against a threshold indicative of sufficient CO;

if the difference between maxPAP|mean and PAD pressure is less than the threshold indicative of sufficient CO, adjusting the pacing parameter to increase CO; and

if the difference between maxPAP|mean and PAD pressure is greater than or equal to the threshold indicative of sufficient CO indicating that the current pacing parameters are sufficiently optimized for further pacing.

9. The method of claim 7 wherein the CRMD is equipped for cardiac resynchronization therapy (CRT) using a selectable set of pacing vectors and the pacing parameter optimized based on CO specifies one or more pacing vectors.

10. The method of claim 1 including performing a further adjustment of pacing parameters based on an assessment of the filling and emptying of the right ventricle (RV) and left atrium (LA) of the heart of the patient.

11. The method of claim 10 wherein assessing the filling and emptying of the RV and LA of the heart of the patient includes:

dividing a PAP waveform corresponding to a cardiac cycle into an RV systolic emptying portion and an LA diastolic filling portion by detecting a dicrotic notch within the PAP waveform;

detecting morphological parameters representative of the RV systolic emptying portion and the LA diastolic filling portion of the PAP waveform; and

adjusting a pacing parameter to improve hemodynamics based on the morphological parameters representative of the RV systolic emptying portion and the LA diastolic filling portion of the PAP waveform.

12. The method of claim 11 wherein the morphological parameters include one or more of the slope, interval duration and area under the curve of the PAP waveform within the RV systolic emptying and the LA diastolic filling portions of the PAP waveform.

13. The method of claim 1 further including:

sensing a left atrial pressure (LAP) signal representative of variations in LAP during individual heart beats; and

detecting MR based, in part, on the LAP signal.

14. The method of claim 13 for use with an implantable cardiac rhythm management device (CRMD) and further including:

adjusting one or more pacing delays based, in part, on the LAP signal.

15. The method of claim 1 wherein at least some of the steps are performed by an external system that receives PAP signals from the implantable PAP sensor.

16. The method of claim 1 wherein at least some of the steps are performed by an implantable cardiac rhythm management device (CRMD) that receives PAP signals from the implantable PAP sensor.

17. A method for use with an implantable pulmonary artery pressure sensor and an implantable cardiac rhythm management device (CRMD) for implant within a patient, the method comprising:

sensing a pulmonary artery pressure (PAP) signal representative of variations in PAP occurring during individual cardiac cycles within the patient;

detecting closure of AV valves within a portion of the PAP signal corresponding to a cardiac cycle;

detecting a ventricular depolarization event (R-wave) within an electrical cardiac signal corresponding to the same cardiac cycle subsequent to the detected closure of the AV valves;

detecting a delay interval (DeltaTime1) between the closure of AV valves and the R-wave detected subsequent to the detected closure of the AV valve; and

adjusting an AV delay based on the delay interval (DeltaTime1).

18. The method of claim 17 wherein the electrical cardiac cycle is one or more of an intracardiac electrogram (IEGM) and a surface electrocardiogram (EKG).

19. The method of claim 17 wherein adjusting the AV pacing delay based on the delay interval (DeltaTime1) includes:

delivering pacing using a current value of the AV pacing delay;

determining whether the closure of AV valves occurs before the R-wave by an amount sufficient so that delay interval (DeltaTime1) is acceptable;

if the closure of AV valves does not occur before the R-wave by an amount sufficient so that DeltaTime1 is acceptable, then adjusting the AV delay; and

if the closure of AV valves does occur before the R-wave by an amount sufficient so that DeltaTime1 is acceptable, then indicating that the current value of the AV pacing delay is sufficiently optimized for further pacing.

20. A method for use with an implantable pulmonary artery pressure sensor and an implantable cardiac rhythm management device (CRMD) for implant within a patient, the method comprising:

sensing a pulmonary artery pressure (PAP) signal representative of variations in PAP occurring during individual cardiac cycles within the patient;

detecting a pulmonary artery systole (PAS) peak within the PAP signal corresponding to a cardiac cycle;

detecting an MR peak within the PAP signal corresponding to the same cardiac cycle;

detecting a second delay interval (DeltaTime2) between the PAS peak and the MR peak; and

adjusting an interventricular (VV) pacing delay based on the second delay interval (DeltaTime2).

21. The method of claim 20 wherein adjusting the VV pacing delay based on the second delay interval (DeltaTime2) includes:

delivering pacing using a current value of the AV delay and a current value of the VV pacing delay;

determining whether the second delay interval (DeltaTime2) is acceptable;

if DeltaTime2 is not acceptable, adjusting the VV pacing delay; and

if DeltaTime2 is acceptable, then indicating that the current value of the VV pacing delay is sufficiently optimized for further pacing.

22. A system for use with an implantable pulmonary artery pressure sensor for implant within a patient, the system comprising:

means for sensing a pulmonary artery pressure (PAP) signal representative of variations in PAP occurring during cardiac cycles of the patient;

means for detecting a rate of change of the PAP signal with time (dPAP/dt), detecting a maximum in the dPAP/dt signal (dPAP/dt|max) and a minimum in the dPAP/dt signal (dPAP/dt|min) within a portion of the PAP signal corresponding to an individual cardiac cycle and examining the dPAP/dt signal within a window between dPAP/dt|max and dPAP/dt|min to detect;

means for detecting a regurgitation peak, if present, within the PAP signal;

means for detecting mitral regurgitation (MR) in the patient based on the MR peaks in the PAP signal;

means for detecting a pulmonary artery systole (PAS) peak within the PAP signal corresponding to a cardiac cycle;

means for detecting a delay interval between the PAS peak and the regurgitation peak; and

means for adjusting a cardiac pacing parameter based, at least in part, on the delay interval.