This document describes implantable medical devices and methods of using such devices. The implantable medical devices include a cardiac lead sized for insertion in a cardiac cavity, the cardiac lead having a distal end and a proximal end and a lead body extending therebetween, a heat exchange module disposed at the distal end of the lead body, the heat exchange module comprising an enclosure having a first surface and a second surface, and one or more temperature sensors located within the enclosure.

Systems and methods for implanting a medical device are provided and include an implantable lead comprising a lead body having a distal end and a proximal end. The implantable lead has electrodes positioned at the distal end and has a lead connector positioned at the proximal end. The lead connector includes lead contacts that are communicatively coupled to the electrodes positioned at the distal end. The lead body has a body outer envelope configured to fit within a lumen of an introducer sheath and the lead connector has a connector outer envelope configured to fit within the lumen of the introducer sheath. A pulse generator has a connector cavity. The lead adaptor is configured to interconnect the implantable lead and the pulse generator. The lead adaptor has an insertable connector that includes mating contacts and an adaptor cavity that includes cavity contacts. The cavity contacts are positioned to engage the lead contacts of the lead connector when the lead connector is inserted into the adaptor cavity. The insertable connector is configured to be inserted into the connector cavity of the pulse generator.

A subcutaneous lead for an implantable cardiac device, in particular for a defibrillator or/and a pacemaker comprising a lead body, itself comprising at least one sensing electrode and an insulating sleeve into which the lead body is threaded so that the insulating sleeve and the lead body are movable relative to each other so as to at least partially cover the at least one sensing electrode with the insulating sleeve.

A subcutaneously implantable device includes a housing, a clip attached to a top side of the housing, a first prong with a proximal end attached to the housing and a distal end extending away from the housing, and a first electrode on the first prong. The clip is configured to anchor the device to a muscle, a bone, and/or a tissue. The first prong is configured to contact a heart. The first electrode is configured to contact the heart. Sensing circuitry in the housing that is configured to sense an electrical signal from the heart, and therapeutic circuitry in the housing is in electrical communication with the first electrode and is configured to deliver electrical stimulation to the heart through the first electrode.

A system for treating cardiac arrhythmias comprising a generator including: a sensing circuitry configured to evaluate one or more identified signals representative of electrical activity of the heart and detect an arrhythmia, a control circuitry that is configured to control delivery of a therapy in response to the detected arrhythmia, the therapy including a first stage of electrical pulses delivered via at least a first electrode, wherein the first set of electrical pulses is configured to destabilize and/or terminate a reentry associated with the arrhythmia, and a first lead coupled to the generator, wherein the first lead includes the first electrode.

An implantable medical system may provide atrioventricular synchronous pacing using the ventricular septal wall. The system may include a ventricular electrode coupled to an intracardiac housing or a first medical lead implantable in the ventricular septal wall of the patient's heart to deliver cardiac therapy to or sense electrical activity of the left ventricle of the patient's heart and a right atrial electrode coupled to a leadlet or second medical lead to deliver cardiac therapy to or sense electrical activity of the right atrium of the patient's heart. A right ventricular electrode may be coupled to the intracardiac housing or the first medical lead and implantable in the ventricular septal wall of the patient's heart to deliver cardiac therapy to or sense electrical activity of the right ventricle of the patient's heart.

An implantable medical device (IMD) is provided and includes electrodes configured to be located in or about a heart. The electrodes include a bipolar electrode combination that define a bipolar sensing vector. The electrodes include a unipolar electrode combination that define a unipolar sensing vector. The IMD includes sensing circuitry configured to define a first sensing channel coupled to the bipolar electrode combination and a second sensing channel coupled to the unipolar electrode combination. The IMD includes memory to store program instructions and one or more processors configured to implement the program instructions to collect cardiac activity (CA) signals over the first and second sensing channels for a series of beats, identify a sensed interval delta (SID) from the CA signals for at least a portion of the series of beats, the SID representing a timing interval between i) a COI in the CA signals collected over the first sensing channel and ii) the same COI in the CA signals collected over the second sensing channel; and designate the series of beats to correspond to be a polymorphic ventricular tachycardia (PVT) or a monomorphic ventricular tachycardia (MVT) based on the SID.

An electrical lead for implantation in a patient is disclosed. The electrical lead can include a distal portion configured to split apart into sub-portions that travel in multiple directions during implantation into the patient and an electrode extension that increases a distance between an electrode and one or more other electrodes on the distal portion of the lead and/or facilitates contact of the electrode with patient tissue.

An implantable medical lead includes a connector, outer lead, inner lead, electrical contact, and conductive element. The connector is configured to electrically communicate with processing circuitry of a medical device. The inner lead, positioned within a lumen defined by the outer lead, is configured to translate relative to the outer lead. The inner lead includes an inner lead electrode and an inner conductor electrically connected to the inner lead electrode, where the inner conductor is configured to electrically communicate with the connector. The outer lead includes an outer lead electrode and an outer conductor electrically connected to the outer lead electrode. The outer conductor is configured to electrically communicate with the connector.

Cardiac therapy devices in the form of pacemakers and/or defibrillators including one or more leads with electrodes implanted in a vein in a posterior position in combination with one or more leads with electrodes implanted in an anterior position. The posterior position may be chosen from one or more of the azygos, hemiazygos, accessory hemiazygos, or posterior intercostal veins. The anterior position may be chosen from the internal thoracic vein, an anterior intercostal vein, or an anterior subcutaneous location. In other examples, sensors are placed for use by a cardiac monitoring or therapy system in one or more of the internal thoracic vein, the azygos vein, the hemiazygos vein, the accessory hemiazygos vein, and/or an anterior or posterior intercostal vein.