Abstract: An implantable medical device system including an atrial pacemaker and a ventricular pacemaker is configured to deliver dual chamber pacing in the presence of atrioventricular block. In response to detecting the AV block, the atrial pacemaker may establish a limited number of selectable pacing rates. The atrial pacemaker selects a rate from the limited number of selectable pacing rates and adjusts the atrial pacing rate to the selected rate. The ventricular pacemaker is configured to establish a ventricular pacing rate that is equivalent to the selected rate in response to detecting the AV block. Other examples are described herein.

Abstract: The present disclosure provides an apparatus and method of detecting ischemia with a pressure sensor. The method can include obtaining a pressure signal and determining a pressure rate of change. The method can also include identifying at least one of impaired relaxation and impaired contractility in order to detect ischemia.

Abstract: An implantable cardioverter defibrillator (ICD) configured to transmit a tissue conduction communication (TCC) signal includes a TCC transmitter module configured to generate the TCC signal and transmit the TCC signal via a plurality of electrodes. The TCC signal comprises a biphasic signal having an amplitude and a frequency, wherein at least one of the amplitude and the frequency are configured to avoid stimulation of tissue of the patient. The TCC transmitter module comprises protection circuitry coupled between a current source and the plurality of electrodes, wherein the protection circuitry is configured to protect the signal generator from an external anti-tachyarrhythmia shock delivered to the patient.

Abstract: An implantable medical device comprises a communication module that comprises at least one of a receiver module and a transmitter module. The receiver module is configured to both receive from an antenna and demodulate an RF telemetry signal, and receive from a plurality of electrodes and demodulate a tissue conduction communication (TCC) signal. The transmitter module is configured to modulate and transmit both an RF telemetry signal via the antenna and a TCC signal via the plurality of electrodes. The RF telemetry signal and the TCC signal are both within a predetermined band for RF telemetry communication. In some examples, the IMD comprises a switching module configured to selectively couple one of the plurality of electrodes and the antenna to the receiver module or transmitter module.

Abstract: A medical device system including an pacemaker implantable in a chamber of a patient's heart is configured to sense near field events from a cardiac electrical signal, establish a lower rate interval to control a rate of delivery of pacing pulses and schedule a first pacing pulse by starting a pacing escape interval set equal to the lower rate interval. The pacemaker withholds the scheduled pacing pulse in response to sensing a near-field event during the pacing escape interval and schedules a next pacing pulse to be delivered at the lower rate interval from a time that the pacing escape interval is scheduled to expire.

Abstract: A medical device system including a pacemaker implantable in an atrial chamber of a patient's heart is configured to sense near field atrial events from a cardiac signal received by a sensing module of the pacemaker and to sense far field ventricular events. The pacemaker is configured to establish an atrial lower rate interval to control a rate of delivery of atrial pacing pulses, determine a rate of the far field ventricular events sensed by the sensing module, determine an atrial event rate, compare the rate of the sensed far field ventricular events to the atrial event rate, and adjust the atrial lower rate interval in response to the comparison.

Abstract: This disclosure provides an extravascular ICD system and method for defibrillating a heart of a patient. The extravascular ICD system includes multiple extravascular electrical stimulation leads or lead segments located in close proximity to one another and having respective defibrillation electrodes. The ICD system utilizes the multiple defibrillation electrodes to form an extravascular electrode vector that may result a reduction in the shock impedance and/or a reduction in the DFT compared to extravascular ICD systems that include only a single extravascular defibrillation electrode. An ICD of the system may, for example, deliver a defibrillation shock using an electrode vector in which a first polarity of the electrode vector is formed by electrically coupling first and second defibrillation electrodes of first and second leads, respectively, to the therapy circuitry and a second polarity of the electrode vector is formed by electrically coupling a housing of the ICD to the therapy circuitry.

Abstract: The present disclosure provides an apparatus and method of detecting ischemia with a pressure sensor. The method can include obtaining a pressure signal and determining a pressure rate of change. The method can also include identifying at least one of impaired relaxation and impaired contractility in order to detect ischemia.

Abstract: In general, the invention is directed to methods and devices for determining an ion concentration in the extracellular fluid of a patient. As examples, the ion may be one or more of potassium, sodium, chloride, or calcium. A system includes an electrode deployed in or near a tissue, such as a skeletal muscle, of the patient. A pulse generator supplies one or more stimulations to the tissue, and a sensor, such as an accelerometer, detects the response of the tissue to the stimulations. A processor determines a concentration of ions in the extracellular fluid as a function of the response. The system may detect an ion imbalance based upon the determined concentration of ions.

Abstract: A method for adjusting a pacing rate in a dual-chamber, leadless pacemaker implanted in a heart may involve determining, with a leadless atrial pacemaker implanted in an atrium of the heart, that an intrinsic atrial contraction rate of the atrium is faster than a ventricular contraction rate, transmitting a first signal from the atrial pacemaker to a leadless ventricular pacemaker implanted in a ventricle of the heart to increase a ventricular pacing rate of the ventricular pacemaker, receiving the transmitted first signal with the ventricular pacemaker, and increasing the ventricular pacing rate, based on the received first signal.

Abstract: A medical device system including an pacemaker implantable in a chamber of a patient's heart is configured to sense near field events from a cardiac electrical signal, establish a lower rate interval to control a rate of delivery of pacing pulses and schedule a first pacing pulse by starting a pacing escape interval set equal to the lower rate interval. The pacemaker withholds the scheduled pacing pulse in response to sensing a near-field event during the pacing escape interval and schedules a next pacing pulse to be delivered at the lower rate interval from a time that the pacing escape interval is scheduled to expire.

Abstract: A medical device system including a pacemaker implantable in an atrial chamber of a patient's heart is configured to sense near field atrial events from a cardiac signal received by a sensing module of the pacemaker and to sense far field ventricular events. The pacemaker is configured to establish an atrial lower rate interval to control a rate of delivery of atrial pacing pulses, determine a rate of the far field ventricular events sensed by the sensing module, determine an atrial event rate, compare the rate of the sensed far field ventricular events to the atrial event rate, and adjust the atrial lower rate interval in response to the comparison.

Abstract: A relatively compact implantable medical device includes a fixation member formed by a plurality of fingers mounted around a perimeter of a distal end of a housing of the device; each finger is elastically deformable from a relaxed condition to an extended condition, to accommodate delivery of the device to a target implant site, and from the relaxed condition to a compressed condition, to accommodate wedging of the fingers between opposing tissue surfaces at the target implant site, wherein the compressed fingers hold a cardiac pacing electrode of the device in intimate tissue contact for the delivery of pacing stimulation to the site. Each fixation finger is preferably configured to prevent penetration thereof within the tissue when the fingers are compressed and wedged between the opposing tissue surfaces. The pacing electrode may be mounted on a pacing extension, which extends distally from the distal end of the device housing.

Abstract: A method for implanting a medical lead. The method includes advancing a tunneling tool posteriorly proximate the caudal end of the sternum toward a first location. The tunneling tool is advanced superiorly underneath the sternum through the anterior mediastinum from the first location to a second location cranial to the first location. A guidewire is advanced from the first location to the second location. A medical lead is slid along at least a portion of the guidewire, the medical lead at least substantially spanning the distance between the first location and the second location.

Abstract: A method and device for implanting a medical lead. The device includes an elongate shaft defining a major longitudinal axis and including a proximal end and a distal end. A necked portion coupled to and extending from the distal end is included, the necked portion defines a first thickness and a substantially planar surface, the necked portion being at least resiliently movable in a direction normal to the major longitudinal axis.

Abstract: A medical device system is configured to sense a physiological signal by a first device and generate a control signal by the first device in response to the physiological signal. An optical transducer is controlled by the first device to emit an optical trigger signal in response to the control signal. A second device receives the optical trigger signal and delivers an automatic therapy to a patient in response to detecting the optical trigger signal.

Abstract: A medical device system is configured to sense physiological events by a first device and control a transducer to emit trigger signals in response to the sensed physiological events. A second device detects the trigger signals and delivers therapeutic stimulation pulses in response to the trigger signals. The therapeutic stimulation pulses have a combined total time duration over the sensed physiological events that is greater than the combined total time duration of the trigger signals.

Abstract: A medical device system is configured to sense a physiological signal by a first device and generate a control signal by the first device in response to the physiological signal. An acoustical emitting device is controlled by the first device to emit an acoustical trigger signal in response to the control signal. A second device detects the acoustical trigger signal and delivers an automatic therapy to a patient in response to detecting the acoustical trigger signal.

Abstract: Embodiments include heart monitoring systems, apparatus, and methods adapted to detect myocardial ischemia. An apparatus includes at least one first-tier sensor/analyzer adapted to sense a first input related to cardiac function, and to produce a first-tier trigger signal when the first input indicates myocardial ischemia. In an embodiment, a first-tier sensor/analyzer includes an ECG sensor/analyzer. In another embodiment, a first-tier sensor/analyzer includes a patient activator. An apparatus further includes at least one second-tier sensor/analyzer adapted to sense a second input related to cardiac function, and to produce a second-tier trigger signal when the second input indicates myocardial ischemia. In an embodiment, a second-tier sensor-analyzer includes a heart sound sensor/analyzer. A triggering element is adapted to produce a response-invoking signal in response to the first-tier trigger signal and the second-tier trigger signal.

Abstract: A medical device system including an intracardiac pacemaker is configured to receive by an implantable medical device sensing module a first cardiac signal using a first pair of electrodes implanted outside the cardiovascular system and identify a P-wave from the first cardiac signal. The system transmits a wireless trigger signal to the intracardiac pacemaker in response to identifying the P-wave. The intracardiac pacemaker delivers a pacing therapy in response to the trigger signal.