35 results about "Left cardiac chamber" patented technology

A system and method for monitoring left ventricular cardiac contractility and for optimizing a cardiac therapy based on left ventricular lateral wall acceleration (LVA) are provided. The system includes an implantable or external cardiac stimulation device in association with a set of leads including a left ventricular epicardial or coronary sinus lead equipped with an acceleration sensor. The device receives and processes acceleration sensor signals to determine a signal characteristic indicative of LVA during isovolumic contraction. A therapy optimization method evaluates the LVA during varying therapy settings and selects the setting(s) that correspond to a maximum LVA during isovolumic contraction. In one embodiment, the optimal inter-ventricular pacing interval for use in cardiac resynchronization therapy is determined as the interval corresponding to the highest amplitude of the first LVA peak during isovolumic contraction.

A method for reversing ventricular dyssynchrony uses intracardiac echocardiographic measured parameters to systematically determine an optimal, individualized configuration for a cardiac resynchronization stimulator device. This method is particularly relevant for patients with congestive heart failure. The algorithm evaluates improvement in aortic flow and in left ventricular ejection fraction as atrioventricular and interventricular delay parameters of the patient's resynchronization stimulator device are varied.

The disclosure provides methods and apparatus of left ventricular pacing including automated adjustment of a atrio-ventricular (AV) pacing delay interval and intrinsic AV nodal conduction testing. It includes—upon expiration or reset of a programmable AV Evaluation Interval (AVEI)—performing the following: temporarily increasing a paced AV interval and a sensed AV interval and testing for adequate AV conduction and measuring an intrinsic atrio-ventricular (PR) interval for a right ventricular (RV) chamber. Thus, in the event that the AV conduction test reveals a physiologically acceptable intrinsic PR interval then storing the physiologically acceptable PR interval in a memory structure (e.g., a median P-R from one or more cardiac cycles). In the event that the AV conduction test reveals an AV conduction block condition or if unacceptably long PR intervals are revealed then a pacing mode-switch to a bi-ventricular (Bi-V) pacing mode occurs and the magnitude of the AVEI is increased.

An application of an invented medicinal composition in preparing the medicines for treating primary hypertension and protecting heart and kidney is disclosed.

The biodegradable microcapsulated ultrasonic contrast medium is a hollow microcapsule with size of 1-10 microns and wall thickness of 50-6000 nm. The preparation process includes the steps of: dissolving biodegradable fatty polylactone with organic solvent to compound solution A; adding emulsifier into distilled water to compound solution B; injecting solution B into solution A via supersonic emulsifying; adding the emulsion into water solution of stabilizer via stirring; stirring for 2-10 hr to separate microcapsules particle and washing with distilled water; and freeze drying the particle to obtain powdered biodegradable microcapsule. Via intravenous injection or intravenous dripping, the present invention may be made to enter myocardial microcirculation via left cardiac chamber and coronary artery for supersonic radiographic examination.

An apparatus comprises a stimulus circuit, a cardiac signal sensing circuit, and a control circuit. The cardiac signal sensing circuit senses a cardiac activity signal using a sensing channel. The stimulus circuit provides electrical pulse energy to a first pacing channel that includes a first left ventricular (LV) electrode and a second pacing channel that includes a second LV electrode. The control circuit initiates delivery of electrical pulse energy using the first and second pacing channels according to a first multi-site LV pacing mode; determines a cardiac event associated with a changein cardiac conduction path using a sensed cardiac activity signal; and changes to a second LV pacing mode in response to determining the cardiac event. The second LV pacing mode is different from thefirst multi-site LV pacing mode in one or more of a pacing site location and inter-electrode stimulus timing.

The invention is directed to methods and devices for optimization of biventricular pacing in subjects suffering from heart failure. The invention provides for a method for selection of optimal parameters for permanent pacing, the method comprising: positioning one or more arrays of lead wires in the posterior pericardium of a subject, wherein the arrays are connected to a multiplexing switch, wherein the switch is connected to a computer processor and a biventricular pacemaker, from the computer processor, generating a randomized sequence of: (i) pacing sites (VPS), (ii) right ventricular-left ventricular delays (RLDs), (iii) heart rates (HR); (iv) atrioventricular delays (AVDs), (v) or any combination or permutation thereof; and determining cardiac output in real time, using aortic flow velocity, thereby allowing selection of optimal parameters for permanent pacing.

Methods and system for atrial fibrillation mapping utilizing cardiac mapping based on medical image(s). The methods and system also adapted for any balloon based catheters including cryoballoon catheter, laser balloon catheter, or “hot balloon” catheter, as well as circular catheters. The methods and system includes overlaying of two or more images on top of each other (where the images are of various types or modalities) and aligning the images, where the transparency between the images can be adjusted for navigating and optimal placement of the balloon based catheters or circular catheters. The cardiac system also adopted for guiding optimal placement of the left ventricular (LV) lead placement for cardiac re-synchronization (CRT) therapy, and for mapping and displaying activation times from various branches of the coronary sinus for optimizing CRT therapy.

The invention provides an automatic ventricular region segmentation method and device for a cardiac ultrasound image and a storage medium, and relates to the technical field of image processing. According to the method, a ventricular region automatic segmentation model is utilized to obtain a segmentation result of each pixel in a to-be-segmented ultrasonic image. According to the ventricular region automatic segmentation model, compared with a traditional UNet method, the network structure of the model is improved, an up-sampling deconvolution layer of a decoder of the model is a multi-dimensional splicing type deconvolution up-sampling layer, the decoder can better obtain image information from multiple dimensions, and then the segmentation accuracy is improved. According to the automatic ventricular region segmentation model, the model training speed and accuracy can be effectively improved, and then the speed and accuracy of automatically segmenting the left ventricular region in the echocardiogram are improved.

The invention provides an ultrasonic cardiogram myocardial abnormal motion mode analysis method and system and a storage medium and relates to the technical field of medical image processing. The method comprises the following steps of acquiring an echocardiogram sequence under a standard four-cavity cardiac tangent plane, wherein the length at least comprises one cardiac cycle; analyzing the leftventricular myocardial wall motion state of the echocardiogram in one cardiac cycle, and extracting multi-dimensional motion mode characteristics; and taking the echocardiogram sequence and the motion mode characteristics as the input of a myocardial abnormal motion mode identification model, and outputting the predicted confidence coefficient of the myocardial abnormal motion mode by using the myocardial abnormal motion mode identification model. According to the method, by extracting the motion mode characteristics in the echocardiogram sequence in one cardiac cycle, the time sequence information and the local motion information in the echocardiogram are fully mined, so accurate myocardial abnormal motion mode analysis can be automatically carried out according to the characteristics, and the prediction result is returned.

Systems and methods are provided for evaluating infranodal pacing is applied to a patient. Electrocardiogram (ECG) data representing the pacing is obtained from a set of electrodes as an ECG lead. A predictor value representing a frequency content a portion of the ECG lead is extracted. A fitness parameter is determined for the pacing from at least the predictor value. The fitness parameter represents a likelihood that the applied infranodal pacing will induce left ventricular dysfunction in the patient. The fitness parameter is displayed to a user at an associated display.

A method and system for delivering a cardiac pacing therapy that includes a cardiac signal being sensed via electrodes of an atrial lead, and an occurrence of one of an intrinsic and a paced atrial depolarization event of a current cardiac cycle being determined in response to the sensed cardiac signal. A first pacing therapy is delivered during the current cardiac cycle in response to the determined occurrence of the depolarization event, and an amplitude of the cardiac signal within the current cardiac cycle subsequent to the delivered first pacing therapy is compared to a predetermined amplitude threshold. A second pacing therapy is delivered, via a left ventricular lead, within the same cardiac cycle and subsequent to the delivered first pacing therapy in response to the amplitude notbeing more negative than the predetermined amplitude threshold and is not delivered in response to the amplitude being more negative than the predetermined amplitude threshold.

The invention is directed to methods and apparatus for automatically changing from bi-ventricular pacing, in which an implantable medical device (IMD) applies pacing stimuli to both ventricles of a heart during a cardiac cycle, to single-ventricle pacing, in which the IMD paces one ventricle and inhibits pacing of the other. An IMD applying the techniques of the invention automatically changes from bi-ventricular pacing to single-ventricle pacing, or vice versa, as a function of the reliability of left ventricular pacing. Exemplary techniques for determining the reliability of left ventricular pacing include impedance measurement, capture testing, capture threshold testing, or any combination thereof.

A method for determining the degree of parallel activation of a heart undergoing pacing includes calculating vectorcardiogram (VCG), or electrocardiogram (ECG), or electrogram (EGM) waveforms from right ventricular pacing (RVp) and left ventricular pacing (LVp). A synthetic biventricular pacing (BIVP) waveform is generated by summing the VCG of the RVp and LVp, or by summing the ECG of the RVp and the LVp, or by summing the EGM of the RVp and the LVp. A corresponding EGM or ECG or VCG waveform from real BIVP is calculated. The method includes comparing the synthetic BIVP waveform and the real BIVP waveform and calculating time to fusion by determining the point in time in which the activation from RVp and LVp meets and the synthetic and the real BIVP curves start to deviate. A delay in time to fusion indicates a higher degree of parallel activation.

An implantable medical device system and method for delivering cardiac resynchronization therapy (CRT) pacing that includes determining capture associated with the delivered CRT pacing is ineffectivein response to the delivered CRT pacing. A reason for capture being ineffective is determined and a safety margin is adjusted if the determined reason for capture being ineffective is loss of captureand a left ventricle (LV) pre-excitation is adjusted if the determined reason for capture being ineffective is delayed LV depolarization. Monitoring for a change in effective cardiac resynchronizationtherapy is used to confirm that the adjustment of the CRT pacing was effective in resolving the ineffective capture.