36 results about "Ventricular conduction" patented technology

The present invention provides a technique for verifying pacing capture of a ventricular chamber, particularly to ensure desired delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or “CRT”). The invention also provides for ventricular capture management by delivering a single ventricular pacing stimulus and checking inter-ventricular conduction during a temporal window to determine if the ventricular pacing stimulus captured the chamber. If a loss-of-capture (LOC) signal results from the capture management testing, then the characteristics of the applied pacing pulses are modified and the conduction test repeated. In the event that the LOC signal persists, a pacing mode-switch to an atrial-based pacing therapy and / or non-bi-ventricular pacing regimen can be implemented.

The present invention provides a technique for verifying pacing capture of a ventricular chamber, particularly to ensure desired delivery of a ventricular pacing regime (e.g., “CRT”). The invention also provides ventricular capture management by delivering a single ventricular pacing stimulus and checking inter-ventricular conduction during a temporal window to determine if the stimulus captured. If a loss-of-capture LOC) signal results from the capture management testing, then the applied pacing pulses are modified and the conduction test repeated. If LOC, an alert message can issue. Other aspects include: use of a trend of A-RV / LV and LV-RV timing intervals to monitor changes in the patient's heart conduction properties; bi-ventricular verification test and search—while still pacing BiV by detecting latent sense; single-V pacing threshold search, use of timing of sense in other V chamber to establish capture and LOC windows; (iv) use of a premature V pace rather than short AV interval if VV cannot be discriminated from AV; (v) option to run a threshold search only if the Bi-ventricular verification test fails.

A method and system for ascertaining the condition of the heart's conduction system in a patient treated for congestive heart failure with pacing therapy. In accordance with the invention, changes in ventricular activation patterns are monitored over time in order to detect changes in the heart's conduction system that may occur due to physiological regeneration of conduction pathways. The activation patterns are reflected by electrogram signals detected from different ventricular locations. By measuring the difference in conduction times of an excitation impulse traveling from the AV node to the different ventricular locations, a parameter representative of the heart's conduction system is obtained that may be used to adjust the pacing therapy in accordance therewith.

The disclosure describes techniques for delivering electrical stimulation to decrease the ventricular rate response during an atrial tachyarrhythmia, such as atrial fibrillation. AV nodal stimulation is employed during an atrial tachyarrhythmia episode with rapid ventricular conduction to distinguish ventricular tachyarrhythmia from supraventricular tachycardia and thereby prevent delivering inappropriate therapy to a patient.

In bi-ventricular pacing devices (including CRT devices) analysis of myocardial electrogram signals in one ventricle (e.g., a left ventricle, or “LV”) can be used to infer capture or loss-of-capture (LOC) of an earlier stimulus pulse in the same ventricle, on a continuous (every pacing cycle), triggered, aperiodic and / or periodic basis. Rather than using an evoked-response principle as has been the basis of capture detection in prior art and other systems, a principle employed via the present invention uses evidence of inter-ventricular conduction (i.e., from the opposite chamber) and / or atrio-ventricular conduction as evidence of LOC, since a non-capturing pacing stimulus provided to a first chamber will allow the myocardial tissue of the first chamber to remain non-refractory and thus inter-ventricular and atrio-ventricular wavefront propagation and conduction can commence and be detected thereby revealing whether LOC has occurred.

The invention relates to a cardiac resynchronization therapy (CRT) method based on self atrioventricular conduction. The method comprises the following steps of implanting a right atrium endocardium electrode and a left ventricle epicardium pace-making electrode in a patient of CRT adaptation diseases; connecting electrodes with a pulse generator; setting parameters of the intelligent pulse generator; executing a scanning search program for collecting real-time electrocardiosignals and left ventricle pace-making commands; performing time fixed point measurement and logic algorithm analysis of scanning search resources by the pulse generator, so as to find an AS / AP-VP interval when the most narrow QRS interval occurs; executing timed CRT by the pulse generator during the AS / AP-VP interval; after the abovementioned process is finished, performing electrocardiosignal collection and pace-making scanning search by the pulse generator, re-finding an AS / AP-VP interval when the most narrow QRS interval occurs; executing timed CRT during the AS / AP-VP interval; and repeating the cycle in such a way. The method is characterized by high intelligent degree, wide application, simple operation and low usage cost.

An implantable pacing system with single, double and triple chamber pacing capabilities, provided individually or in concert on a conditional or continuous basis depending upon ongoing analyses of atrial rhythm status, atrioventricular conduction status and ventricular rate. A mode is selected to reduce the occurrence of any ventricular pacing in favor of intrinsic atrioventricular and ventricular conduction. If excessively long PR intervals are occurring too frequently or atrioventricular conduction is unreliable or absent, the implantable pulse generator is operated in a conditional triple chamber pacing mode that provides atrial-synchronous biventricular pacing in every cardiac cycle for a period of time as necessary to restore and maintain AV synchrony, while minimizing ventricular asynchrony otherwise associated with monochamber RV pacing as in conventional dual chamber pacing systems. Similarly, biventricular pacing is provided in every cardiac cycle when ventricular rates are undesirably slow during atrial fibrillation, where AV synchronization is excluded.

An implantable medical device and a method for operating such a device to provide cardiac pacing to the heart of a patient for pacing hearts of patients suffering from periodical or intermittent atrio-ventricular blocks, for example, AV block or HIS block. A control circuit operates the device in a DDI-II mode, the DDI-II mode being an operation mode with an atrial inhibited pacing and a DDI-II mode ventricular pacing rate being lower than a predetermined base rate of a pulse circuit of the device, during periods with atrio-ventricular conduction conditions. If a block in atrio-ventricular conduction is detected and at least one first switching criterion is satisfied, the control circuit causes a switching circuit to switch from the DDI-II mode to the DDI mode and, if a block in atrio-ventricular conduction is detected and at least one second switching criterion is satisfied, the control circuit causes the switching circuit to switch from the DDI mode to the DDD mode. The control circuit is adapted to control the switching circuit to switch back to the DDI-II mode at satisfaction of a reinitiating criterion.

An implantable pacing system with single, double and triple chamber pacing capabilities, provided individually or in concert on a conditional or continuous basis depending upon ongoing analyses of atrial rhythm status, atrioventricular conduction status and ventricular rate. A mode is selected to reduce the occurrence of any ventricular pacing in favor of intrinsic atrioventricular and ventricular conduction. If excessively long PR intervals are occurring too frequently or atrioventricular conduction is unreliable or absent, the implantable pulse generator is operated in a conditional triple chamber pacing mode that provides atrial-synchronous biventricular pacing in every cardiac cycle for a period of time as necessary to restore and maintain AV synchrony, while minimizing ventricular asynchrony otherwise associated with monochamber RV pacing as in conventional dual chamber pacing systems. Similarly, biventricular pacing is provided in every cardiac cycle when ventricular rates are undesirably slow during atrial fibrillation, where AV synchronization is excluded.

An implantable pacing system with single, double and triple chamber pacing capabilities, provided individually or in concert on a conditional or continuous basis depending upon ongoing analyses of atrial rhythm status, atrioventricular conduction status and ventricular rate. A mode is selected to reduce the occurrence of any ventricular pacing in favor of intrinsic atrioventricular and ventricular conduction. If excessively long PR intervals are occurring too frequently or atrioventricular conduction is unreliable or absent, the implantable pulse generator is operated in a conditional triple chamber pacing mode that provides atrial-synchronous biventricular pacing in every cardiac cycle for a period of time as necessary to restore and maintain AV synchrony, while minimizing ventricular asynchrony otherwise associated with monochamber RV pacing as in conventional dual chamber pacing systems. Similarly, biventricular pacing is provided in every cardiac cycle when ventricular rates are undesirably slow during atrial fibrillation, where AV synchronization is excluded.

An improvement to the GiWi protocol for differentiating human pluripotent cells to developmentally mature cardiomyocytes includes a step of activating innate immunity in mesoderm stage cells in the in vitro differentiation culture. When the mesoderm cells, which are precursors to cardiac progenitor cells, are primed by exposure to an activator of innate immunity, a population of cardiomyocytes is generated that is more developmentally mature than is generated in the GiWi protocol without the primed step. Also provided herein are in vitro ventricular conductive microtissues and isolated, in vitro populations of ventricular conduction system-like cells and methods for making the same.

The present invention provides compounds effective as sphingosine-1-phosphate receptor modulators for the treatment of cardiopulmonary disorders such as hypertension (including malignant hypertension), angina, myocardial infarction, arrhythmia , congestive heart failure, coronary heart disease, atherosclerosis, angina, dysrhythmia, cardiomyopathy (including hypertensive cardiomyopathy), heart failure, cardiac arrest, bronchitis, asthma, chronic obstructive pulmonary disease, cystic fibrosis , croup, emphysema, pleurisy, pulmonary fibrosis, pneumonia, pulmonary embolism, pulmonary hypertension, mesothelioma, ventricular conduction abnormalities, complete cardiac obstruction, adult respiratory distress syndrome, sepsis syndrome, idiopathic pulmonary Fibrosis, scleroderma, systemic sclerosis, retroperitoneal fibrosis, prevention of keloid formation, or cirrhosis.