A method for pacing left bundle branch of the heart comprising implantation of a multi-electrode lead at a desired depth into the interventricular septum from the right ventricle, wherein the depth control during the implantation of the distal electrode is provided by monitoring electrical impedance for one or more intermediate electrodes. Reaching of exceeding a threshold of electrical impedance change is used to determine the entry of a corresponding intermediate electrode from the blood stream in the right ventricle into the cardiac tissue of the septum. Known distances between intermediate spaced apart electrodes and the distal electrode allow determination of the implantation depth of the distal electrode.

Techniques for evaluating cardiac electrical dyssynchrony are described. In some examples, an activation time is determined for each of a plurality of torso-surface potential signals. The dispersion or sequence of these activation times may be analyzed or presented to provide variety of indications of the electrical dyssynchrony of the heart of the patient. In some examples, the locations of the electrodes of the set of electrodes, and thus the locations at which the torso-surface potential signals were sensed, may be projected on the surface of a model torso that includes a model heart. The inverse problem of electrocardiography may be solved to determine electrical activation times for regions of the model heart based on the torso-surface potential signals sensed from the patient.

The present disclosure pertains to cardiac pacing methods and systems, and, more particularly, to cardiac resynchronization therapy (CRT). In particular, the present disclosure pertains to determining whether a patient is experiencing atrial fibrillation (AF). If the patient is experiencing AF, the efficacy of CRT is determined. A signal is sensed in response to a ventricular pacing stimulus. Through signal processing, a number of features are parsed from the signal and a determination is made as to whether the ventricular pacing stimulus evoked a response from the ventricle.

This disclosure relates to an active implantable medical device of the cardiac resynchronizer type. The device includes a pulse generator to produce pacing pulses, at least one detection electrode for detecting atrial and ventricular events, at least one stimulation electrode, a memory storing executable instructions, and a processor configured to execute the instructions. The processor is configured to execute the instructions to apply an atrioventricular delay (AVD) between a sensed or stimulated atrial event and the delivery of a ventricular pacing pulse, quantify a degree of fusion between the delivery of a pacing pulse to a cavity and a spontaneous contraction of another cavity, calculate a fusion rate, and modify the value of the AVD applied to the delivery of said ventricular pacing pulse, as a function of a comparison.

Systems and methods for controlling blood pressure by controlling atrial pressure and atrial stretch are disclosed. In some embodiments, a stimulation circuit may be configured to deliver a stimulation pulse to at least one cardiac chamber of a heart of a patient, and at least one controller may be configured to execute delivery of one or more stimulation patterns of stimulation pulses to the at least one cardiac chamber, wherein at least one of the stimulation pulses stimulates the heart such that an atrial pressure resulting from atrial contraction of an atrium overlaps in time a passive pressure build-up of the atrium, such that an atrial pressure of the atrium resulting from the stimulation is a combination of the atrial pressure resulting from atrial contraction and the passive pressure build-up and is higher than an atrial pressure of the atrium would be without the stimulation, and such that the blood pressure of the patient is reduced.

Methods and systems for use of the Q-wave to R-wave interval to guide placement of a leadless cardiac pacemaker are disclosed. An implant delivery device is equipped with sensing electrodes to sense R-wave onset in a ventricle of a patient's heart to allow placement at a location of last or latest onset of the R-wave. Guidance tools are provided to assist in determination of the Q-wave to R-wave interval during implantation. For a chronic system, a cooperative approach is disclosed in which an implantable medical device and a leadless cardiac pacemaker exchange data to determine Q-wave to R-wave intervals and enhance cardiac resynchronization therapy delivery by the leadless cardiac pacemaker.

A leadless cardiac pacemaker is adapted for implantation into triangle of Koch or His bundle with a plurality of individual electrodes spread in the vicinity of implantation site. Individual electrodes are first evaluated for their suitability for sensing and pacing of atrial and ventricular chambers of the heart. Individual electrodes are then selected for delivery of cardiac pacing to multiple heart chambers from a single intra-cardiac location. Remaining non-selected individual electrodes may be abandoned. Also described is an adapter with multiple electrodes configured to dock with a conventional leadless or standard pacemaker to operate in the same way.

The embodiments described herein relate to a self-positioning, quick-deployment low profile transvenous electrode system for sequentially pacing both the atrium and ventricle of the heart in the dual chamber mode, and methods for deploying the same.

A biventricular (BiV) implantable cardiac stimulator contains a stimulation control unit, one or more stimulation units, an impedance measurement unit and an impedance evaluation unit. The stimulation control unit is operatively connected to one or more stimulation units to control delivery of stimulation pulses by the one or more stimulation units. The stimulation control unit is configured to assess ventricular contractility based on an impedance signal generated by the impedance evaluation unit and to switch between at least a univentricular left ventricular stimulation mode and a biventricular stimulation mode and to evaluate the ventricular contractility in relation to the respective ventricular stimulation mode.

An implantable system detecting electrical signals of a human or animal heart includes a processor, a memory unit, a first detection unit for atrial activity, a second detection unit for right ventricular activity and a third detection unit for left ventricular activity. The system automatically performs steps at regular intervals including detecting an intrinsic right atrial activity using the first detection unit; detecting an intrinsic right ventricular activity using the second detection unit; determining a time between the intrinsic right atrial activity and the intrinsic right ventricular activity, and storing this time as atrioventricular conduction time. Additionally or alternatively the steps include detecting an intrinsic right ventricular activity using the second detection unit; detecting an intrinsic left ventricular activity using the third detection unit; and determining a time between the intrinsic right ventricular activity and the intrinsic left ventricular activity, and storing this time as interventricular conduction time.