34 results about "Atrioventricular conduction" patented technology

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.

Techniques are provided for use by implantable medical devices for controlling ventricular pacing. In one example, optimal atrio-ventricular and interventricular pacing delay values are determined for pacing the heart of the patient based, in part, on a measured inter-atrial conduction delay. Atrio-ventricular conduction delays are then measured within the patient. The atrio-ventricular pacing delays are compared with the measured atrio-ventricular conduction delays. If the atrio-ventricular pacing delays are less than the measured atrio-ventricular conduction delays, biventricular pacing is delivered using the atrio-ventricular pacing delay and the interventricular pacing delay. However, if the atrio-ventricular pacing delays are not less than the corresponding atrio-ventricular conduction delays, as can occur if the inter-atrial conduction delay is large, then alternative pacing regimes are selectively enabled, such as monoventricular pacing in the chamber having the longer conduction delay value, biventricular pacing with negative hysteresis, or biventricular pacing with pacing delays reduced using predetermined offset values.

An exemplary method includes delivering a cardiac resynchronization therapy using an atrio-ventricular delay parameter and an interventricular delay parameter, measuring an atrio-ventricular conduction delay, measuring an interventricular conduction delay, assessing heart failure and / or cardiac resynchronization therapy performance based at least in part on the measured atrio-ventricular conduction delay and the measured interventricular conduction delay and determining at least one of an atrio-ventricular delay parameter value and an interventricular delay parameter value based at least in part on the measured atrio-ventricular conduction delay and the measured interventricular conduction delay. Other exemplary technologies are also disclosed.

A method discriminates between ventricular arrhythmia and supraventricular arrhythmia by determining the direction of an electrical signal conducted through the atrioventricular node. An implantable cardiac defibrillator provides atrioventricular and ventriculoatrial pacing bursts to determine if an arrhythmia with a 1:1 atrial to ventricular relationship is due to ventricular tachycardia or supraventricular tachycardia. This discrimination capability reduces the incidence of inappropriate shocks from dual-chamber implantable cardiac defibrillators to near zero and provides a method to differentially diagnose supraventricular tachycardia from ventricular tachycardia.

Techniques are provided 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, it is believed that 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.

Cardiac pacemaker, having at least one stimulation pulse generator to selectively generate stimulation pulses for delivery to an atrium or to an atrium and a ventricle of a heart in DDD mode, at least one sensing stage adapted to process electrical signals sensed by an atrial and ventricular sensing electrode to detect an atrial or ventricular event and to generate an atrial or ventricular sense signal upon event detection, a control unit connected to the generator and sensing stage and being adapted to trigger the generator in DDD mode, wherein the control unit is adapted to verify proper atrioventricular conduction and to switch from a regular (DDD) mode, wherein scheduled ventricular stimulation pulses having predetermined positive intensity is triggered unless inhibited to a ventricular pulse suppression mode (VPS mode) wherein no ventricular stimulation pulses or ventricular stimulation pulses of sub-threshold intensity are generated as long as proper atrioventricular conduction is verified.

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.

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.

Techniques are provided for use by implantable medical devices for controlling ventricular pacing. In one example, optimal atrio-ventricular and interventricular pacing delay values are determined for pacing the heart of the patient based, in part, on a measured inter-atrial conduction delay. Atrio-ventricular conduction delays are then measured within the patient. The atrio-ventricular pacing delays are compared with the measured atrio-ventricular conduction delays. If the atrio-ventricular pacing delays are less than the measured atrio-ventricular conduction delays, biventricular pacing is delivered using the atrio-ventricular pacing delay and the interventricular pacing delay. However, if the atrio-ventricular pacing delays are not less than the corresponding atrio-ventricular conduction delays, as can occur if the inter-atrial conduction delay is large, then alternative pacing regimes are selectively enabled, such as monoventricular pacing in the chamber having the longer conduction delay value, biventricular pacing with negative hysteresis, or biventricular pacing with pacing delays reduced using predetermined offset values.

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 nifedipine medicine composition and a preparation method thereof. The nifedipine medicine composition contains nifedipine, hydroxymethyl propyl cellulose and microcrystalline cellulose. The hydroxymethyl propyl cellulose is used as slow-releasing framework material; the weight ratio of the nifedipine and the hydroxymethyl propyl cellulose is 2:1-1:1; and the weight ratio of the nifedipine and the microcrystalline cellulose is 1:4-1:3; and lactose, starch, calcium hydrophosphate and glucose can be also added. The method for preparing the nifedipine medicine composition comprises the following steps of: (1) crushing and screening; (2) drying; and (3) tabletting. According to the invention, the dissolution rate of the nifedipine in the water can be increased, the coronary arteries in the normal blood supply area and the ischemic area are relaxed while the absorption rate of the nifedipine in the body is increased so that coronarospasm and is released and prevented and myocardial contraction is inhibited; myocardial oxygen consumption is reduced; the peripheral resistance is released; after load of heart is reduced; sinus node function and atrioventricular conduction of the isolated heart are slowed down; and the nifedipine medicine composition is applicable to variant angina pectoris, unstable angina pectoris and chronic stable angina pectoris.

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.

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 medical device including a control unit, at least a right ventricular sensing unit and / or a right atrial sensing unit, wherein the right ventricular sensing unit is connected or can be connected to a right ventricular stimulation electrode lead having at least one electrode pole and a stimulation unit that is connected or can be connected to a multipolar left ventricular stimulation electrode lead having a plurality of electrode poles. The control unit is adapted to determine right atrioventricular conduction state and to cause selection of one of the plurality of electrode poles of the multipolar left ventricular stimulation electrode lead depending a respective determined right atrioventricular conduction state.

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.

The invention relates to a compound anti-arrhythmic drug which is composed of a calcium antagonist verapamil or diltiazem and digitalis drug. The positive inotropic effect of the digitalis drug can resist the negative inotropic effect of the verapamil or the diltiazem, while the effect of delaying the atrioventricular conduction thereof can strengthen the treatment effect of delaying the atrioventricular conduction of the verapamil or the diltiazem. In the compound drug, the used dose of the verapamil or the diltiazem is reduced, thus increasing safety and expanding scope of application.

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.

The invention provides a cardiac pace making system which comprises a perception module, a pace making module and a control module. Under a normal atrioventricular conduction condition, the control module controls the cardiac pace making system to work in a first mode and detect whether atrioventricular block occurs; various atrioventricular block events can be judged accurately by sensing and comparing PR (punctum remotum) intervals and ventricular event missing; when the atrioventricular block occurs, the control module controls the cardiac pace making system to work in a second mode; and acardiac pacemaker can timely work in an appropriate mode and provide an appropriate AV (atrioventricular) time sequence and a ventricular rhythm.

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 without damage to liver and kidney.

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 provides a cardiac pacemaker which comprises a control module and a perception module. The cardiac pacemaker can be switched into second modes to work during atria ventricular block, atria ventricular conduction recovery can be simultaneously detected by the perception module under the control of the control module by means of AV (atria ventricular) conduction section search according to preset periods, the cardiac pacemaker can be switched into first modes to work when atria ventricular conduction recovery is detected by the perception module, the preset periods include C waiting intervals which are sequentially arranged, a waiting interval is available after each section of AV conduction section search, each later waiting interval is not shorter than the corresponding previous waiting interval, and the last waiting interval in the preset periods is longer than the first waiting interval. Compared with existing cardiac pacemakers, the cardiac pacemaker in the configuration has the advantages that the cardiac pacemaker is reasonable in atria ventricular conduction recovery detection frequency, and right ventricular pacing can be reduced as far as possible on the basisthat the atria ventricular stability is guaranteed.

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.

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.