CARDIAC CONTRACTILITY MODULATION IN ASSOCIATION WITH RESPIRATION
A system comprising: one or more sensors for detecting parameters of a respiratory cycle in a patient; and an implantable cardiac device comprising: at least one lead comprising one or more electrodes for applying cardiac contractility modulation stimulation to the heart; and circuitry for controlling and activating the leads, the circuitry programmed to set parameters of the cardiac contractility modulation stimulation according to the parameters of the respiratory cycle detected by the one or more sensors.
1 . A method of operating an implanted cardiac device configured for delivery of cardiac contractility modulation stimulation to the heart, comprising:
tracking at least one respiration cycle parameter using one or more sensors; and
automatically setting, at a controller of said implanted cardiac device, one or more parameters of cardiac contractility modulation stimulation according to said at least one respiration cycle parameter; wherein said automatically setting one or more parameters of cardiac contractility modulation stimulation comprises setting the timing of the cardiac contractility modulation stimulations to be applied during one or more selected time intervals of the respiratory cycle, as tracked by said one or more sensors.
2 . The method according to claim 1 , wherein said at least one respiration cycle parameter is selected from the group of: a respiration rate, a relative timing of exhalation and/or inhalation, a duration of exhalation and/or inhalation.
3 . The method according to claim 1 , wherein said one or more selected time intervals of the respiratory cycle include one or more time intervals in which there is a larger relative anatomical space between the heart and the diaphragm and/or a larger relative anatomical space between the heart and the phrenic nerve.
4 . The method according to claim 3 , comprising synchronizing timing for applying the cardiac contractility modulation stimulation with timing in which the diaphragm is farthest from the heart and/or with timing in which the phrenic nerve is farthest from the heart.
5 . The method according to claim 1 , wherein said automatically setting one or more parameters of cardiac contractility modulation stimulation comprises setting timing for applying the cardiac contractility modulation stimulation, said timing being during an absolute refractory period of the cardiac cycle.
6 . The method according to claim 1 , wherein said one or more sensors are selected from the group of: an acoustic sensor, a pulse oximeter, a pneumograph, a capnograph.
7 . The method according to claim 1 , wherein said one or more sensors include an intra-cardiac electrode which records ECG, and wherein said determining at least one respiration cycle parameter is based on said ECG recording.
8 . The method according to claim 1 , wherein said automatically setting one or more parameters of cardiac contractility modulation stimulation comprises setting a current intensity of the cardiac contractility modulation stimulation at the highest level which does not cause pain.
9 . The method according to claim 1 , wherein said automatically setting one or more parameters of cardiac contractility modulation stimulation comprises setting a rate for applying multiple cardiac contractility modulation stimulations.
10 . The method according to claim 9 , comprising increasing the rate of cardiac contractility modulation stimulations when detecting a rise in respiration rate, and decreasing the rate of cardiac contractility modulation stimulations when detecting decrease in respiration rate.
11 . The method according to claim 1 , wherein said cardiac device is implanted in a patient diagnosed with heart failure.
12 . The method according to claim 1 , one or more selected time intervals of the respiratory cycle include one or more time intervals in which there is a larger distance between at least one lead of said implanted cardiac device and the phrenic nerve.
13 . The method according to claim 12 , wherein said one or more time intervals are selected by testing during which time interval(s) said applying does not cause or only least causes sensation to the patient.
14 . The method according to claim 12 , wherein said one or more time intervals include a time interval which is during the inhalation period.
15 . The method according to claim 12 , wherein said one or more time intervals include a time interval which is during the exhalation period.
16 . The method according to claim 12 , comprising recording an ECG of the patient and selecting a time for applying of cardiac contractility modulation stimulation when an amplitude of the R wave of a current cardiac cycle is higher than an average R wave amplitude calculated based on at least 5 previous cardiac cycles.
17 . The method according to claim 12 , comprising recording an ECG of the patient and selecting a time for applying of cardiac contractility modulation stimulation when an amplitude of the R wave of a current cardiac cycle is lower than an average R wave amplitude calculated based on at least 5 previous cardiac cycles.
18 . The method according to claim 12 , comprising recording an ECG of the patient and selecting a time for applying of cardiac contractility modulation stimulation when the RR interval of a current cardiac cycle is longer than an average RR interval calculated based on at least 5 previous cardiac cycles.
19 . The method according to claim 12 , comprising recording an ECG of the patient and selecting a time for applying of cardiac contractility modulation stimulation when the RR interval of a current cardiac cycle is shorter than an average RR interval calculated based on at least 5 previous cardiac cycles.
20 . The method according to claim 1 , wherein said tracking at least one respiration cycle parameter comprises detecting a dyspnea episode, and applying cardiac contractility modulation stimulation in response.
21 . The method according to claim 1 , further comprising assessing, according to the at least one measured respiration cycle parameter, cardiac output and/or respiratory output over time and timing the applying of cardiac contractility modulation stimulation accordingly.
22 . The method according to claim 12 , comprising assessing if the patient has sensed the cardiac contractility modulation stimulation, and selecting a different time interval of the respiratory cycle for applying of said cardiac contractility modulation stimulation if the stimulation was sensed.
23 - 50 . (canceled)
51 . The method according to claim 1 , wherein said automatically setting comprises selecting said one or more parameters of cardiac contractility modulation stimulation taking into account anatomical changes occurring during the respiration cycle.
52 . The method according to claim 1 , comprising skipping the applying of said cardiac contractility modulation stimulation during one or more cardiac cycles or during one or more respiratory cycles based on said tracked parameters of the respiratory cycle.
53 - 54 . (canceled)