ENHANCING LEFT VENTRICULAR RELAXATION THROUGH NEUROMODULATION
Neuromodulation is used to enhance left ventricular relaxation. An exemplary neuromodulation system includes a therapy element positionable in proximity to at least one nerve fiber, and a stimulator configured to energize the therapy element to delivery therapy to the at least one nerve fiber such that left ventricular relaxation and left ventricular contractility are contemporaneously enhanced.
1 - 23 . (canceled)
24 . A method of treating a patient having a left ventricular contractility (LVC) and a left ventricular relaxation (LVR), comprising:
using a mechanical circulatory support device to increase cardiac output or aid in unloading the heart; and
while using the mechanical circulatory support device, delivering neuromodulation therapy to contemporaneously enhance LVC and LVR.
25 . The method of claim 24 , wherein the neuromodulation therapy includes:
using at least one therapy element to neuromodulate at least one parasympathetic nerve fiber to increase LVR and to neuromodulate at least one sympathetic nerve fiber to increase LVC.
26 . The method of claim 24 , wherein the neuromodulation therapy is delivered to contemporaneously enhance LVC and LVR such that the ratio of the percentage increase of LVC to the percentage increase of LVR is within a predetermined range.
27 . The method of claim 26 , wherein the predetermined range is 0.5-1.5.
28 . The method of claim 26 , wherein the predetermined range is 0.8-1.2.
29 . The method of claim 26 , wherein the predetermined range is approximately 1.0.
30 . The method of claim 24 , wherein the step of delivering neuromodulation therapy includes positioning at least one therapy element in an intravascular location and neuromodulating an extravascular nerve fiber using the therapy element.
31 . The method of claim 30 , wherein the intravascular location is selected from the group of blood vessels consisting of the superior vena cava, left brachiocephalic vein and right brachiocephalic vein.
32 . The method of claim 30 , wherein the intravascular location is selected from the group of blood vessels consisting of the superior vena cava, left brachiocephalic vein, lower internal jugular vein, right brachiocephalic vein, azygos vein or azygos arch.
33 . The method of claim 25 , wherein the steps of neuromodulating the parasympathetic and sympathetic nerve fibers are performed contemporaneously.
34 . The method of claim 25 , wherein the steps of neuromodulating the parasympathetic and sympathetic nerve fibers are performed at different times.
35 . The method of claim 24 , wherein the enhancement of LVR is determined by determining the increase in a value selected from left ventricular dP/dt min in diastole, arterial blood pressure (ABP) in diastole, tau in diastole, mitral valve deceleration time, mitral valve velocity time interval or end diastolic pressure volume relationship (EDPVR) from prior to initiation of neuromodulation to after initiation of neuromodulation.
36 . The method of claim 24 , wherein the enhancement of LVC is determined by determining the increase in the value selected from left ventricular dP/dt max in systole, ABP in systole, from prior to initiation of neuromodulation to after initiation of neuromodulation.
37 . The method of claim 24 , wherein the mechanical circulatory support device is selected from the group of mechanical circulatory support devices consisting of blood pumps, ventricular assist devices, percutaneous ventricular assist devices, and intra-aortic balloon pumps.
38 . The method of claim 26 , wherein the neuromodulation therapy is delivered by a neuromodulation system, and wherein the method further includes receiving by the neuromodulation system LVR input corresponding to a measure of LVR and LVC input corresponding to a measure of LVC, the neuromodulation system automatically adjusting at least one neuromodulation parameter such that the ratio of the enhancement of LVC to the enhancement of LVR is within the predetermined range.
39 . A system for treating a patient having a left ventricular contractility (LVC) and a left ventricular relaxation (LVR), comprising:
a mechanical circulatory support device positionable to enhance circulation of blood in the patient to increase cardiac output or aid in unloading the heart; and
a neuromodulation system for enhancing left ventricular relaxation (LVR) and left ventricular contractility (LVC), the neuromodulation system comprising at least one neuromodulation therapy element adapted for positioning in proximity to at least one nerve fiber and a stimulator configured to energize said at least one therapy element to deliver therapy to the at least one nerve fiber, such that the LVR and LVC are contemporaneously enhanced.
40 . The system of claim 39 , wherein the neuromodulation system includes wherein neuromodulation therapy element is adapted for positioning within a blood vessel and the stimulator is configured to energize said at least one therapy element within the blood vessel to deliver therapy to said at least one nerve fiber disposed external to the blood vessel, such that the LVR and LVC are contemporaneously enhanced.
41 . The system of claim 39 wherein the stimulator is configured to energize the therapy element such that the ratio of the enhancement of LVC to the enhancement of LVR is within a predetermined range.
42 . The system of claim 39 , further including at least one sensor adapted to deliver LVR input to the system corresponding to a measure of LVR and to deliver LVC input to the system corresponding to a measure of LVC.
43 . The system of claim 42 wherein the system is configured to determine the enhancement of LVR by comparing the measure of LVR from prior to initiation of neuromodulation to said selected measure after initiation of neuromodulation, and to determine the enhancement of LVR by comparing the measure of LVR from prior to initiation of neuromodulation to said selected measure after initiation of neuromodulation.
44 . The system of claim 43 , wherein the measure of LVR is selected from the set of measures consisting of left ventricular dP/dt min in diastole, arterial blood pressure (ABP) in diastole, tau in diastole, mitral valve deceleration time or mitral valve velocity time interval.
45 . The system of claim 43 , wherein the measure of LVC is selected from the set of measures consisting of left ventricular dP/dt max in systole, ABP in systole, increases in stroke volume without changes in pre-load (i.e. left ventricular end diastolic pressure), afterload (i.e. systemic vascular resistance) or end systolic pressure volume relationship (ESPVR).
46 . The system of claim 43 wherein the system is configured to automatically adjust at least one neuromodulation parameter such that the ratio of the enhancement of LVC to the enhancement of LVR is within a predetermined range.
47 . The system of claim 46 , wherein the therapy elements are electrodes and the neuromodulation parameter adjusted by the system is at least one of electrical currents, voltages, and pulse widths, pulse frequency, charge density, effective electrode surface area, effective electrode spacing, and electrode combinations energized.
48 . The system of claim 41 , wherein the predetermined range is 0.5-1.5.
49 . The system of claim 41 , wherein the predetermined range is 0.8-1.2.
50 . The system of claim 41 , wherein the predetermined range is approximately 1.0.
51 . The system of claim 39 , wherein the mechanical circulatory support device is selected from the group of mechanical circulatory support devices consisting of blood pumps, ventricular assist devices, percutaneous ventricular assist devices, and intra-aortic balloon pumps.
52 . The system of claim 42 , wherein said at least one sensor is positioned on a portion of the mechanical circulatory support device that during use is disposed within the circulatory system.
53 . The system of claim 39 , wherein the neuromodulation system includes:
a parasympathetic therapy element intravascularly positionable to neuromodulate at least one parasympathetic nerve fiber to increase LVR; and
a sympathetic therapy element intravascularly positionable to neuromodulate at least one sympathetic nerve fiber to increase LVC.
54 - 65 . (canceled)