Abstract: Exemplary methods are described for providing responsive vascular control with or without cardiac pacing. An implantable device with responsive vascular and cardiac controllers interprets physiological conditions and responds with an appropriate degree of vascular therapy applied as electrical pulses to a sympathetic nerve. In one implementation, an implantable device is programmed to deliver the vascular therapy in response to low blood pressure or orthostatic hypotension. The device may stimulate the greater splanchnic nerve, to effect therapeutic vasoconstriction. The vascular therapy is dynamically adjusted as the condition improves. In one implementation to benefit impaired physical mobility, vascular therapy comprises vasoconstriction and is timed to coincide with a recurring segment of the cardiac cycle. The vasoconstriction assists circulation and venous return in the lower limbs of inactive and bedridden individuals.

Abstract: Implantable systems, and methods for use therewith, are provided for monitoring for an impending myocardial infarction. A signal indicative of changes in arterial blood volume is obtained. Such a signal can be a photoplethysmography signal or an impedance plethysmography signal. For each of a plurality of periods of time, a metric indicative of the areas under the curve of the signal or number of inflections in the signal is determined. An impending myocardial infarction is monitored for based on changes in the metric indicative of the area under the curve of the signal or number of inflections in the signal, and an alert and/or therapy is triggered in response to an impending myocardial infarction being predicted.

Abstract: Techniques are provided for use with an implantable cardiac rhythm management (CRMD) system equipped to deliver neurostimulation to acupuncture sites within anterior regions of the neck, thorax or abdomen of the patient. Parameters associated with the health of the patient are detected, such as parameters indicative of arrhythmia, heart failure and hypertension.

Abstract: In an implantable medical device for monitoring glucose concentration in the blood, a blood-glucose concentration analysis is performed using correlations of blood-glucose concentration with measures of metabolic oxygen consumption including oxymetric, and/or temperature. Analysis of electrocardiographic data is used in a parallel method to detect and/or confirm the onset and/or existence and/or extent of hypoglycemia and/or hyperglycemia. Blood-glucose concentration calculation is enhanced by using the combination of the oxygen metabolism analysis and electrocardiographic analysis.

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial electrical stability. A patient's heart is paced for a period of time using a patterned pacing sequence that repeats every N beats, and an electrical signal is obtained that is representative of a plurality of consecutive beats of the patient's heart while it is being paced using the patterned pacing sequence that repeats every N beats. Myocardial electrical stability is then analyzed using frequency domain techniques that are tailored to the patterned pacing sequence used to pace the patient's heart. In other embodiments, the patient's heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial mechanical stability based on a signal that is indicative of mechanical functioning of a patient's heart for a plurality of consecutive beats. Certain embodiments use time domain techniques, while other embodiments use frequency domain techniques, to monitor myocardial mechanical stability. In certain embodiments the patient's heart is paced using a patterned pacing sequence that repeats every N beats. In other embodiments, the patient's heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: Techniques are provided for controlling neurostimulation such as spinal cord stimulation (SCS) using a cardiac rhythm management device (CRMD). In various examples described herein, neurostimulation is delivered to a patient while regional cardiac performance of the heart of the patient is assessed by the CRMD. The delivery of further neurostimulation is adjusted or controlled based, at least in part, on the regional cardiac performance, preferably to enhance positive effects on the heart due to the neurostimulation or to mitigate any negative effects. Regional cardiac performance is assessed based on parameters derived from cardiogenic impedance signals detected along various vectors through the heart.

Abstract: Embodiments of the present invention relate to implantable systems, and method for use therein, that can detect myocardial ischemic events. In accordance with specific embodiments of the present invention, short-term fluctuations in cardiac intervals that follow premature ventricular contractions (PVCs) are monitored. This allows myocardial ischemic events to be detected based on these monitored fluctuations. The cardiac intervals for which fluctuations are being monitored can be, for example, RR intervals. Alternatively, or additionally, short-term fluctuations in other types of cardiac intervals may be monitored. Such other cardiac intervals include, for example, PR intervals, PP intervals, QT intervals and RT intervals.

Abstract: Methods and systems are provided to deliver a neural stimulation (NS) therapy utilizing a first NS operating configuration to assist anti-tachycardia pacing (ATP) therapy in response to a detected tachyarrhythmia. Before and after delivering of the NS therapy, characteristic values are measured for a rate-related physiologic characteristic (rate RPC) and a stability-related physiologic characteristic (stability RPC). The rate RPC is indicative of a frequency of a reentrant circuit within the tachyarrhythmia. The stability RPC is indicative of a hemodynamic stability of the reentrant circuit. The pre-NS and post-NS characteristic values for the rate and stability RPCs are analyzed to determine a rate RPC difference and a stability RPC difference. Different ATP therapies are delivered based on the type associated with the tachyarrhythmia, the rate RPC difference and the stability RPC difference.

Abstract: A bioelectric battery may be used to power implantable devices. The bioelectric battery may have an anode electrode and a cathode electrode separated by an insulating member comprising a tube having a first end and a second end, wherein said anode is inserted into said first end of said tube and said cathode surrounds said tube such that the tube provides a support for the cathode electrode. The bioelectric battery may also have a membrane surrounding the cathode to reduce tissue encapsulation. Alternatively, an anode electrode, a cathode electrode surrounding the cathode electrode, a permeable membrane surrounding the cathode electrode. An electrolyte is disposed within the permeable membrane and a mesh surrounds the permeable membrane. In an alternative embodiment, a pacemaker housing acts as a cathode electrode for a bioelectric battery and an anode electrode is attached to the housing with an insulative adhesive.

Abstract: Provided herein are implantable systems, and methods for use therewith, for characterizing a tachycardia and/or selecting treatment for a tachycardia using results of a fractionation analysis. One or more electrogram (EGM) signal(s) indicative of cardiac electrical activity are obtained. At least one of the EGM signal(s) is analyzed to determine whether the EGM signal is fractionated, and the results of the analyzing are used to characterize a tachycardia and/or to select treatment for a tachycardia.

Abstract: Implantable systems, and methods for use therein, perform at least one of a cardiac assessment and an autonomic assessment. Premature atrial contractions (PACs) are induced to thereby cause corresponding premature contractions in the ventricles. Short-term fluctuations in cardiac intervals, that follow the premature contractions in the ventricles caused by the induced PACs, are monitored. At least one of a cardiac assessment and an autonomic assessment is performed based on the monitored fluctuations in cardiac intervals that follow the premature contractions in the ventricles caused by the induced PACs. This can include assessing a patient's risk of sudden cardiac death (SCD), assessing a patient's autonomic tone and/or detecting myocardial ischemic events based on the monitored fluctuations in cardiac intervals that follow the premature contractions in the ventricles caused by the induced PACs.

Abstract: Embodiments of the present invention relate to monitoring a patient's atrial stretch, heart failure (HF) condition, and/or risk of atrial fibrillation (AF), as well as methods for estimating a change in at least one of a patient's left atrial pressure (LAP), pulmonary capillary wedge pressure (PCWP), and right pulmonary artery pressure (RPAP). Embodiments of the present invention also relate to selecting a pacing energy level. Such embodiments involve determining atrial evoked response metrics when a patient's atrium is paced, and monitoring changes in such metrics.

Abstract: Embodiments of the present invention are directed to implantable systems, and methods for use therewith, that monitor and modify a patient's arterial blood pressure without requiring an intravascular pressure transducer. In accordance with an embodiment, for each of a plurality of periods of time, there is a determination one or more metrics indicative of pulse arrival time (PAT), each of which are indicative of how long it takes for the left ventricle to generate a pressure pulsation that travels from the patient's aorta to a location remote from the patient's aorta. Based on the one or more metrics indicative of PAT, the patient's arterial blood pressure is estimated. Changes in the arterial blood pressure are monitored over time. Additionally, the patient's arterial blood pressure can be modified by initiating and/or adjusting pacing and/or other therapy based on the estimates of the patient's arterial blood pressure and/or monitored changes therein.

Abstract: Techniques are provided for use with an implantable cardiac stimulation device equipped for multi-site left ventricular (MSLV) pacing using a multi-pole LV lead. In one example, referred to herein as QuickStim, cardiac pacing configurations are optimized based on an assessment of hemodynamic benefit and device longevity. In another example, referred to herein as QuickSense, cardiac sensing configurations are optimized based on sensing profiles input by a clinician. Various virtual sensing channels are also described that provide for the multiplexing or gating of sensed signals. Anisotropic oversampling is also described.

Abstract: In one embodiment, an implantable stimulation apparatus includes a vagal nerve stimulator configured to generate electrical pulses below a cardiac threshold of a heart, and an electrode coupled to the vagal nerve stimulator which is configured to transmit the electrical pulses below the cardiac threshold, to a vagal nerve so as to inhibit injury resulting from an ischemia and/or reduce injury resulting from an ischemia. In another embodiment, an implantable stimulation apparatus includes a vagal nerve stimulator configured to generate electrical pulses below a cardiac threshold, and includes an electrode, which is coupled to the vagal nerve stimulator and configured transmit electrical pulses to a vagal nerve so as to reduce a defibrillation threshold of the heart.

Abstract: Implantable systems and method for use therewith are provided that take advantage of various neuromodulation and neurosensing techniques for either preventing atrial fibrillation (AF) or terminating AF. Specific embodiments are for use with an implantable device that includes one or more atrial electrode for sensing atrial fibrillation (AF) and/or delivering Atrial Anti-Tachycardia Pacing (AATP) and one or more electrode for monitoring and/or stimulating atrial vagal fat pads.

Abstract: Implantable systems, and methods for use therewith, are provided for monitoring a patient's diastolic function and/or heart failure (HF) condition. A signal indicative of changes in arterial blood volume and a signal indicative of electrical activity of the patient's heart are obtained. Beginnings of diastolic periods can be detected based on a feature of the signal indicative of changes in arterial blood volume. Ends of the diastolic periods can be detected based on a feature of the signal indicative of electrical activity of the patient's heart, or on the signal indicative of changes in arterial blood volume. Diastolic periods (DPs), isovolumic relaxation times (IVRTs) and/or diastolic filling times (DiFTs) can be estimated based on the detected beginnings of the diastolic periods and detected ends of the diastolic periods. The patient's diastolic function and/or HF condition (and/or changes therein) can be monitored based on the estimates of DP, IVRT and/or DiFT.

Abstract: Systems and method for assessing a patient's myocardial electrical stability by pacing a patient's heart using a pacing sequence that includes at least two different types of pacing pulses. The pacing rate used is preferably only slightly above the patient's intrinsic heart rate. A degree of alternans, in a signal (e.g., IEGM or ECG) that is indicative of cardiac activity in response to the pacing sequence, is determined. The degree of alternans can be determined by comparing portions of the signal that are indicative of cardiac activity in response to the first type of pacing pulses to portions of the signal that are indicative of cardiac activity in response to the second type of pacing pulses. The patient's myocardial electrical stability is assessed based on the determined degree of alternans.

Abstract: Methods of processing venous oxygen saturation and hematrocrit information in an implantable sensor are provided. In an embodiment a method for collecting data from an implantable multi-wavelength SvO2 sensor having multiple light sources is provided. The method includes receiving a frame signal that indicates a beginning of the light sources being turned on and receiving a light source signal that indicates a light source is on. The output of a photodetector is sampled to measure the intensity of the transmitted light. The process is repeated for each light source to gather intensity measurements that then can be used to generate venous oxygen saturation and hematocrit measurements.