摘要:
Systems and methods for detecting and measuring cardiac contractile function of a heart using an acceleration sensor unit inserted within the heart, such as within a vein of the cardiac wall are disclosed. The systems and methods involve detecting the occurrence of electrical events within the patient's heart by inserting and positioning an implantable lead having an electrode near a cardiac wall as well as detecting mechanical events within the patient's heart by then inserting and positioning a cardiac motion sensor unit through the inner lumen of the implantable lead. Furthermore, the systems and methods do not require dedicated leads and may be used with preexisting implantable leads.
摘要:
A method or system for computing and/or setting optimal cardiac resynchronization pacing parameters as derived from intrinsic conduction data is presented. The intrinsic conduction data includes intrinsic atrio-ventricular and interventricular delay intervals which may be collected via the sensing channels of an implantable cardiac device. Among the parameters which may be optimized in this manner are an atrio-ventricular delay interval and a biventricular offset interval. In one of its aspects, the invention provides for computing optimum pacing parameters for patients having some degree of AV block or with atrial conduction deficits. Another aspect of the invention relates to a pacing mode and configuration for providing cardiac resynchronization therapy to patients with a right ventricular conduction disorder.
摘要:
A method and apparatus for predicting acute response to cardiac resynchronization therapy is disclosed. The method can comprise measuring a first interval during an intrinsic systolic cycle and measuring a second interval during a stimulated systolic cycle. The acute response can be predicted by comparing the percent change in duration between the first interval and the second interval against a pre-determined threshold value. The first and second time intervals can be measured using, for example, a surface ECG or, alternatively, an intracardiac electrogram. In one embodiment, the first interval can be the duration of an intrinsic QRS complex measured during a non-stimulated systolic cycle. Similarly, the second interval can be the duration of a stimulated QRS complex measured during a stimulated systolic cycle.
摘要:
A method and apparatus for selection of one or more ventricular chambers to stimulate for ventricular resynchronization therapy. Intrinsic intracardia electrograms that include QRS complexes, are recorded from a left and right ventricle. A timing relationship between the intrinsic intracardia electrograms recorded from the left and right ventricle is then determined. In one embodiment, the timing relationship is determined using a delay between a left ventricular and a right ventricular sensed intrinsic ventricular depolarizations and a duration interval of one or more QRS complexes. In one embodiment, the duration of QRS complexes is determined from either intracardiac electrograms or from surface ECG recordings. One or more ventricular chambers in which to provide pacing pulses are then selected based on the timing relationship between intrinsic intracardia electrograms recorded from the right and left ventricle, and the duration of one or more QRS complexes.
摘要:
A method and apparatus for determining whether a patient with congestive heart failure (CHF) will benefit from pacing therapy through the use of an implantable cardiac rhythm management device. A patient's right ventricular and left ventricular pressures are measured, and the patient's PP_Area is calculated for each normal heartbeat that occurs during the testing period. Depending upon the value of the patient's mean PP_Area, it can be determined whether the patient will or will not respond well acutely to pacing therapy. A mean PP_Area value of greater than or equal to a predetermined threshold, which is about 0.3, indicates that the patient is a responder to pacing therapy, while a value of less than the predetermined threshold of about 0.3 indicates that the patient is a non-responder.
摘要:
An apparatus comprises an implantable cardiac signal sensing circuit that provides an electrical cardiac signal representative of cardiac activity of a subject, an implantable therapy circuit that delivers electrical pacing stimulation energy to a heart of a subject, and a controller circuit. The controller circuit includes a chronotropic incompetence detection circuit that initiates pacing of an atrium of the subject at a rate higher than a device-indicated rate or a sensed intrinsic rate, monitor the AV interval, initiates an increase in the pacing rate while continuing the monitoring of the AV interval, calculates a change in AV intervals between a highest paced rate used in the monitoring and a lowest paced rate used in the monitoring, and indicates that the AV intervals are evidence of chronotropic incompetence when the calculated change in the AV intervals exceeds a specified threshold AV interval change value.
摘要:
A cardiac rhythm management system modulates the delivery of pacing and/or autonomic neurostimulation pulses based on heart rate variability (HRV). An HRV parameter being a measure of the HRV is produced to indicate a patient's cardiac condition, based on which the delivery of pacing and/or autonomic neurostimulation pulses is started, stopped, adjusted, or optimized. In one embodiment, the HRV parameter is used to evaluate a plurality of parameter values for selecting an approximately optimal parameter value.
摘要:
A system comprises a cardiac signal sensing and a processing circuit. The cardiac signal sensing circuit senses a first cardiac signal segment that includes a QRS complex and a second cardiac signal segment that includes a fiducial indicative of local ventricular activation. The processor circuit includes a site activation timer circuit configured to determine a time duration between a fiducial of the QRS complex of the first cardiac signal segment and the fiducial of the second cardiac signal segment. The processor circuit is configured to generate, using the determined time duration, an indication of optimality of placement of one or more electrodes for delivering therapy and provide the indication to at least one of a user or process.
摘要:
At least one of a left intraventricular conduction defect, a right intraventricular conduction defect, or no intraventricular conduction defect can be detected using received intrinsic cardiac information from a subject, and a first atrioventricular (AV) delay can be calculated using a first relationship if the left intraventricular conduction defect or no intraventricular conduction defect is detected, or a second AV delay can be calculated using a second relationship if the right intraventricular conduction defect is detected.
摘要:
Systems and methods involve determination of CRT parameters using a number of CRT optimization processes. Each CRT optimization process attempts to return recommended parameters. The CRT parameters are determined based on the recommended parameters returned by one or more of the CRT optimization processes. The CRT optimization processes may be sequentially implemented and the CRT parameters may be determined based on the recommended parameters returned by a first CRT optimization process to return recommended parameters. The CRT parameters may be determined based on a combination of the recommended parameters returned. The CRT optimization processes implemented may be selected from available CRT optimization processes based on patient conditions.