Dislodgement of a defibrillation lead from the right ventricle to the right atrium is a rare complication associated with implantable cardioverter-defibrillators. However, such dislodgement deserves attention out of proportion to its low incidence because of the possibility to cause fatal proarrhythmia. Various embodiments are directed to algorithms for detecting lead dislodgement, including a primary algorithm that operates during baseline rhythm and a secondary algorithm that operates during detection of ventricular tachycardia or ventricular fibrillation to identify lead dislodgement during atrial fibrillation.

An extra-cardiovascular implantable cardioverter defibrillator (ICD) system receives a cardiac electrical signal by an electrical sensing circuit via an extra-cardiovascular sensing electrode vector and senses cardiac events from the cardiac electrical signal. The ICD system detects tachycardia from the cardiac electrical signal and determines a tachycardia cycle length from the cardiac electrical signal. The ICD system determines an ATP interval based on the tachycardia cycle length and sets an extended ATP interval that is longer than the ATP interval. The ICD delivers ATP pulses to a patient's heart via an extra-cardiovascular pacing electrode vector different than the sensing electrode vector. The ATP pulses include a leading ATP pulse delivered at the extended ATP interval after a cardiac event is sensed from the cardiac electrical signal and a second ATP pulse delivered at the ATP interval following the leading ATP pulse.

A subcutaneous implantable cardioverter-defibrillator (S-ICD) comprising shocking electrodes configured to reduce the defibrillation threshold. The S-ICD may include a canister housing a source of electrical energy, a capacitor, and operational circuitry that senses heart rhythms and an electrode and lead assembly. The electrode and lead assembly may comprise a lead, at least one sensing electrode, and at least one shocking electrode. The at least one shocking electrode may extend over a length in the range of 50 to 110 millimeters and a width in the range of 1 to 40 millimeters.

Tunneling tools and systems comprising electrodes and tunneling tool. In some examples the tunneling tools have a width that is greater than thickness, or may have enlarged portions to allow tunneling of a space. The tunneling tools may have expandable dissection portions including expandable balloons, linkages and/or springs in different examples. Systems may include tunneling tools with a lumen for receiving a lead having an electrode in a collapsed configuration, where the electrode is designed to expand once placed in a patient, with the tunneling tool designed to create a space in which the electrode can expand.

Coronary access and delivery systems are provided. A coronary access system can include a coronary sinus guide and a first core. A lateral vein delivery system can include a lateral vein introducer and a second core. The coronary sinus guide, the lateral vein introducer, and the first and second cores may be designed or shaped to access a predetermined position within a heart of a subject. For example, the coronary sinus guide, the lateral vein introducer, and/or the first and second cores can be used in combination to access the predetermined position within the heart of the subject.

The disclosure relates to a device including a plurality of electrodes for stimulation of both ventricles with application of an atrioventricular delay and of an interventricular delay, a processor configured to multidimensionally measure an interventricular conduction delay, and monitor the evolution of a patient's condition. For the multidimensional measurement of the interventricular conduction delay, the device produces stimulation of one of the ventricles and collects, in the other ventricle, two endocardial electrogram signals on separate respective channels, giving two respective temporal components. Both temporal components are combined in one single parametric 2D characteristic representative of the cardiac cycle, and a comparison is made with reference descriptors for deriving an index representative of the evolution of the patient's condition.

According to some embodiments, a device operates by comparative morphological analysis of depolarization signals collected in spontaneous rhythm on separate respective channels, with two temporal components combined into a single 2D parametric VGM vectogram characteristic. Similarity quantification methods evaluate a variation over time of a descriptor parameter of a current VGM compared to a stored previous reference VGM. This variation is compared with predetermined thresholds to diagnose an occurrence of remodeling or reverse remodeling in a patient, and/or to detect a lead failure or an occurrence of ischemia. The descriptor parameter is a function of a velocity vector of the VGM, a comparison relating to a correlation coefficient between respective magnitudes of a current VGM velocity vector and of a reference VGM velocity vector, and an average angle between these respective velocity vectors.

An ICD multimode system comprises a microcontroller or FPGA having a memory, a differentially driven phased array amplifier, one or more sensors, and a wireless transmitter/receiver. Based upon sensor data and demand criteria programmed into the memory, the system provides late systolic impulse (LSI) therapy to treat congestive heart failure (CHF), ventricle level-shifting (VLS) therapy to block unwanted PVCs to prevent VT or VF, and cardiac resynchronization therapy (CRT) that adjusts LV and RV contraction synchronization based upon timing. An integrated echocardiogram and ultrasound system automatically adjusts the therapies administered based upon sensor and demand data in real time to allow a patient's heart to function at a level of improved performance and efficiency.

Brugada syndrome and related forms of ion channelopathies, including ventricular asynchrony of contraction, originate in the region near the His bundle or para-Hisian regions of the heart. Manifestations of Brugada syndrome can be corrected by delivering endocardial electrical stimulation coincident to the activation wave front propagated from the atrioventricular (AV) node early enough to compensate for the conduction problems that start in those region. The stimulation can include waveforms of the same or different polarity delivered to a site within the region near the His bundle or para-Hisian regions of the heart associated with a low cardiac electrical asynchrony level or can include at least two single-phased superimposed waveforms of opposite polarity delivered through a pair of pacing electrodes relative to a reference electrode, which can be delivered to any site within the region near the His bundle or para-Hisian regions of the heart.

An implantable extravascular electrode lead, having a proximal end and a distal end, comprises an electrode lead body that extends from the proximal end of the electrode lead to the distal end of the electrode lead, a connecting device arranged at the proximal end of the electrode lead body, and a fixing device arranged in the distal region of the electrode lead body or at the distal end of the electrode lead body. Once the electrode lead has been inserted into an extravascular region of a patient, the fixing device is actively actuatable from outside the body for fixing the electrode lead to patient body tissue.