34 results about "Atrioventricular conduction" patented technology

A pacing system provides for optimal hemodynamic cardiac function for parameters such as ventricular synchrony or contractility (peak left ventricle pressure change during systole or LV+dp / dt), or stroke volume (aortic pulse pressure) using system for calculating atrio-ventricular delays for optimal timing of a ventricular pacing pulse. The system deriving the proper timing using electrical or mechanical events having a predictable relationship with an optimal ventricular pacing timing signal. A look-up table relating the timing of such electrical or mechanical events to atrio-ventricular delay time intervals is provided for programming the pacing system.

A system and method for estimating optimal atrioventricular delay values for use in pacing the ventricles. Both the intrinsic inter-atrial conduction delay and the intrinsic atrioventricular conduction delay are determined for the patient and then the preferred atrioventricular pacing delay is derived therefrom. By taking into account intrinsic inter-atrial delay along with intrinsic atrioventricular delay, a more reliable estimate of the true optimal atrioventricular delay values for the patient can be achieved than with techniques that only take into account intrinsic atrioventricular delay values. In one example, the technique uses intracardiac electrogram (IEGM) signals and surface electrocardiogram (EKG) signals and hence can be performed by an external programmer without requiring Doppler echocardiography or other cardiac performance monitoring techniques. In another example, wherein the implanted device is equipped with a coronary sinus lead, the technique uses only IEGM signals and hence can be performed by the device itself.

Embodiments of the invention provide systems and methods for an implantable medical device comprising means for selecting between an atrial chamber reset (ACR) test and an atrioventricular conduction (AVC) test to provide atrial capture management and means for switching between an atrial-based pacing mode and a dual chamber pacing mode based on detecting relatively reliable atrioventricular conduction.

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.

Techniques are provided for use by implantable medical devices for controlling ventricular pacing, particularly during atrial fibrillation. In one example, during a V sense test for use in optimizing ventricular pacing, the implantable device determines relative degrees of variation within antecedent and succedent intervals detected between ventricular events sensed on left ventricular (LV) and right ventricular (RV) sensing channels. Preferred or optimal ventricular pacing delays are then determined, in part, based on a comparison of the relative degrees of variation obtained during the V sense test. In another example, during RV and LV pace tests, the device distinguishes QRS complexes arising due to interventricular conduction from QRS complexes arising due to atrioventricular conduction from the atria, so as to permit the determination of correct paced interventricular conduction delays for the patient. The paced interventricular conduction delays are also used to optimize ventricular pacing. Biventricular and monoventricular pacing regimes are provided.

Techniques are provided for use by implantable medical devices for controlling ventricular pacing, particularly during atrial fibrillation. In one example, during a V sense test for use in optimizing ventricular pacing, the implantable device determines relative degrees of variation within antecedent and succedent intervals detected between ventricular events sensed on left ventricular (LV) and right ventricular (RV) sensing channels. Preferred or optimal ventricular pacing delays are then determined, in part, based on a comparison of the relative degrees of variation obtained during the V sense test. In another example, during RV and LV pace tests, the device distinguishes QRS complexes arising due to interventricular conduction from QRS complexes arising due to atrioventricular conduction from the atria, so as to permit the determination of correct paced interventricular conduction delays for the patient. The paced interventricular conduction delays are also used to optimize ventricular pacing. Biventricular and monoventricular pacing regimes are provided.

The invention discloses a Chinese medicinal preparation for treating atrioventricular conduction block, which is prepared from the following raw materials in part by weight: 35 to 85 parts of luvunga, 30 to 80 parts of obscured homalomena rhizome, 25 to 75 parts of pilose asiabell root, 20 to 70 parts of danshen root, 10 to 40 parts of turmeric root-tuber, 15 to 60 parts of nutgrass galingale rhizome, 15 to 60 parts of red paeony root and 25 to 70 parts of Indian buead. The Chinese medicinal preparation for treating the atrioventricular conduction block has the effects of soothing sinews and quickening network vessels, freeing heart yang, quickening blood and dispelling stasis, supplementing center and boosting vital energy, moving vital energy and resolving depression, coursing liver vital energy, moving depression and eliminating stagnation, benefiting spleen and stomach, quieting heart and soothing nerves. The Chinese medicinal preparation is unique in medication and reasonable in medicament property, and has obvious curative effect of preventing and curing the atrioventricular conduction block. The Chinese medicinal preparation is the pure Chinese medicinal preparation withoutdamage to liver and kidney.

The present invention provides a cardiac pace making system. The cardiac pace making system comprises a sensing module, a pace making module, and a control module. Under a normal atria ventricular conduction condition, the control module controls the cardiac pace making system to work in a first mode and detect whether an atria ventricular block has occurred; various atria ventricular block events are determined accurately by sensing and comparing PR intervals and missed ventricular events; when an atria ventricular block occurs, the control module controls the cardiac pace making system to work in a second mode, so that a cardiac pacemaker may work in a timely manner and in an appropriate mode and provide an appropriate AV time sequence and ventricular rhythm.