Abstract: A pacemaker has a housing and a therapy delivery circuit enclosed by the housing for generating pacing pulses for delivery to a patient's heart. An electrically insulative distal member is coupled directly to the housing and at least one non-tissue piercing cathode electrode is coupled directly to the insulative distal member. A tissue piercing electrode extends away from the housing.

Abstract: This disclosure provides various embodiments of implant tools and implant techniques utilizing those tools. In one embodiment, an implant tool comprises a handle and a shaft. The shaft includes a proximal end adjacent the handle, a distal end, an open channel that extends from near the proximal end to the distal end, and at least one lumen that extends from a proximal end of the shaft to a location near the distal end of the shaft. The implant tool may also include a coupler configured to connect to a fluid delivery device. In one example, the fluid delivery device may be a syringe. In some instances, the handle of the implant tool may include a compartment or a recess configured to receive the fluid delivery device.

Abstract: Techniques and methods for determining the number and type of leads that are connected to an implantable medical device (IMD) system are disclosed. The IMD system is configured having at least two modes of operation, the modes of operation corresponding to the number and type of leads that are coupled to the IMD system. In accordance with aspects of the disclosure, one of the at least two modes may be selected based on the determination of the number and type of leads that are connected to the IMD system.

Abstract: Techniques and methods for determining the number and type of leads that are connected to an implantable medical device (IMD) system are disclosed. The IMD system is configured having at least two modes of operation, the modes of operation corresponding to the number and type of leads that are coupled to the IMD system. In accordance with aspects of the disclosure, one of the at least two modes may be selected based on the determination of the number and type of leads that are connected to the IMD system.

Abstract: An implantable cardiac defibrillator (ICD) system includes an ICD implanted subcutaneously in a patient, a defibrillation lead having a proximal portion coupled to the ICD and a distal portion having a defibrillation electrode configured to deliver a defibrillation or cardioversion shock to a heart of the patient, and a pacing lead that includes a distal portion having one or more electrodes and a proximal portion coupled to the ICD. The distal portion of the pacing lead is implanted at least partially along a posterior side of a sternum of the patient within the anterior mediastinum. The ICD is configured to provide pacing pulses to the heart of the patient via the pacing lead and provide defibrillation shocks to the patient via the defibrillation lead. As such, the implantable cardiac system provides pacing from the substernal space for an extravascular ICD system.

Abstract: Substernal implantable cardioveter-defibrillator (ICD) systems and methods for providing substernal electrical stimulation therapy to treat malignant tachyarrhythmia, e.g., ventricular tachycardia (VT) and ventricular fibrillation (VF) are described. In one example, an implantable cardioveter-defibrillator (ICD) system includes an ICD implanted in a patient and an implantable medical electrical lead. The lead includes an elongated lead body having a proximal end and a distal portion, a connector at the proximal end of the lead body configured to couple to the ICD, and one or more electrodes along the distal portion of the elongated lead body. The distal portion of the elongated lead body of the lead is implanted substantially within an anterior mediastinum of the patient and the ICD is configured to deliver electrical stimulation to a heart of the patient using the one or more electrodes.

Abstract: According to this disclosure, a non-transvenous pacing and, optionally defibrillation, therapy device is implanted subcutaneously and oriented to provide cardiac sensing from electrodes spaced from a heart and deliver pacing and/or defibrillation from one or more non-transvenous electrodes (e.g., an epicardial or pericardial electrode or electrode patch). A subject receiving a device according to this disclosure is monitored to confirm a relatively stable bundle branch block (i.e., delayed activation) of one ventricle. The subcutaneous device has electrodes disposed on the housing and/or having an electrode on a subcutaneous medical lead is oriented so that the pacing (and sensing) vector impinges mainly upon the one ventricle, and/or optionally an epicardial or pericardial lead is deployed to a last-to-depolarize ventricle (e.g., a left ventricle) so that single-ventricular pacing is delivered to achieve fusion depolarization of both ventricles.