Managing preload reserve by tracking the ventricular operating point with heart sounds
First Claim
1. A method comprising:
- monitoring an S1 heart sound emitted by a heart of a patient;
monitoring a proxy variable indicating preload exhibited by the heart;
determining whether the heart has exhibited an inotropic state change, using at least the S1 heart sound and the proxy variable.
1 Assignment
0 Petitions
Accused Products
Abstract
A system and method for managing preload reserve and tracking the inotropic state of a patient'"'"'s heart. The S1 heart sound is measured as a proxy for direct measurement of stroke volume. The S3 heart sound may be measured as a proxy for direct measurement of preload level. The S1-S3 pair yield a point on a Frank Starling type of curve, and reveal information regarding the patient'"'"'s ventricular operating point and inotropic state. As an alternative, or in addition to, measurement of the S3 heart sound, the S4 heart sound may be measured or a direct pressure measurement may be made for the sake of determining the patient'"'"'s preload level. The aforementioned measurements may be made by a cardiac rhythm management device, such as a pacemaker or implantable defibrillator.
27 Citations
32 Claims
-
1. A method comprising:
-
monitoring an S1 heart sound emitted by a heart of a patient;
monitoring a proxy variable indicating preload exhibited by the heart;
determining whether the heart has exhibited an inotropic state change, using at least the S1 heart sound and the proxy variable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A method comprising:
-
sensing a plurality of S3 or S4 heart sounds emitted by a heart of a patient, each of which is represented as a time-varying signal with at least one maxima and minima;
finding a greatest difference between a minima and maxima that are consecutive for each of the time-varying signals representing the plurality of S3 or S4 heart sounds, yielding a set of peak-to-peak differences; and
monitoring an inotropic state of the heart, using the set of peak-to-peak differences and an indicator of stroke volume. - View Dependent Claims (15, 16, 17, 18)
-
-
19. A system comprising:
-
a preload altering device;
an implantable device including a transducer;
a control circuit coupled to the transducer, the control circuit configured to cooperate with the transducer to monitor an S1 heart sound emitted by a heart of a patient, monitor a proxy variable indicating preload exhibited by the heart, and communicate a control signal to the preload altering device. - View Dependent Claims (20, 21, 22, 23, 24, 25)
-
-
26. A system comprising:
-
an inotropic state altering device; and
an implantable device including a transducer; and
a control circuit coupled to the transducer, the control circuit configured to cooperate with the transducer to monitor an S1 heart sound emitted by a heart of a patient, monitor a proxy variable indicating preload exhibited by the heart, and communicate a control signal to the inotropic state altering device using the inotropic state. - View Dependent Claims (27, 28)
-
-
29. An implantable device comprising:
-
a transducer; and
a control circuit coupled to the transducer, the control circuit configured to cooperate with the transducer to monitor an S1 heart sound emitted by a heart of a patient, and monitor a proxy variable indicating preload exhibited by the heart. - View Dependent Claims (30, 31, 32)
-
Specification