摘要:
Cardiac lead implantation systems, devices, and methods for lead implantation are disclosed. An illustrative cardiac lead implantation system comprises a mapping guidewire including one or more electrodes configured for sensing cardiac electrical activity, a signal analyzer including an analysis module configured for analyzing an electrocardiogram signal sensed by the mapping guidewire, and a user interface configured for monitoring one or more hemodynamic parameters within the body. The sensed electrical activity signal can be used by the analysis module to compute a timing interval associated with ventricular depolarization.
摘要:
Cardiac lead implantation systems, devices, and methods for lead implantation are disclosed. An illustrative cardiac lead implantation system comprises a mapping guidewire including one or more electrodes configured for sensing cardiac electrical activity, a signal analyzer including an analysis module configured for analyzing an electrocardiogram signal sensed by the mapping guidewire, and a user interface configured for monitoring one or more hemodynamic parameters within the body. The sensed electrical activity signal can be used by the analysis module to compute a timing interval associated with ventricular depolarization.
摘要:
An implantable medical device such as an implantable pacemaker or implantable cardioverter/defibrillator includes a programmable sensing circuit providing for sensing of a signal approximating a surface electrocardiogram (ECG) through implanted electrodes. With various electrode configurations, signals approximating various standard surface ECG signals are acquired without the need for attaching electrodes with cables onto the skin. The various electrode configurations include, but are not limited to, various combinations of intracardiac pacing electrodes, portions of the implantable medical device contacting tissue, and electrodes incorporated onto the surface of the implantable medical device.
摘要:
An exhaust gas purifying catalyst includes two catalyst layers containing a fire resistant inorganic compound carrying a catalyst component in an exhaust gas passage of a base material provided with the exhaust gas passage penetrating through the base material from the exhaust gas introduction port side to discharge port side, wherein each catalyst layer is formed by supporting the catalyst component on a different fire resistant inorganic compound, a catalyst layer extended from the exhaust gas introduction port side to the exhaust gas discharge port side and a catalyst layer extended from the exhaust gas discharge port side to the exhaust gas introduction port side are formed such that the catalyst layers are overlapped on each other and the exhaust gas introduction port side is coated only with one of the catalyst layers and the exhaust gas discharge port side is coated only with the other.
摘要:
An implantable medical device such as an implantable pacemaker or implantable cardioverter/defibrillator includes a programmable sensing circuit providing for sensing of a signal approximating a surface electrocardiogram (ECG) through implanted electrodes. With various electrode configurations, signals approximating various standard surface ECG signals are acquired without the need for attaching electrodes with cables onto the skin. The various electrode configurations include, but are not limited to, various combinations of intracardiac pacing electrodes, portions of the implantable medical device contacting tissue, and electrodes incorporated onto the surface of the implantable medical device.
摘要:
An implantable cardiac rhythm management device is programmed and configured to detect a death event. When such an event is detected, the device ceases recording of physiological data, thus preserving in the device's memory the data collected at and shortly before the time of death. A death event may be detected by detecting of an absence of intrinsic electrical activity in the patient's heart and a lack of an evoked response to a predetermined number of pacing pulses.
摘要:
A cardiac electrical stimulation system that enhances the ability of the system to automatically detect whether an electrical stimulus results in heart capture or contraction. The cardiac electrical stimulation system may be utilized, for example, as a cardiac pacer or as a cardioverter defibrillator. The cardiac electrical stimulation system includes an electrical stimulation circuit that attenuates polarization voltages or “afterpotential” which develop at the heart tissue/electrode interface following the delivery of a stimulus to the heart tissue, which thereby allows the stimulation electrodes to be utilized to sense an evoked response to the electrical stimulus. The cardiac electrical stimulation system utilizes the stimulation electrodes to sense an evoked response, thereby eliminating the necessity for an indifferent electrode to sense an evoked response. The present invention allows accurate detection of an evoked response of the heart, to thereby determine whether each electrical stimulus results in capture.
摘要:
A maximum pacing rate limiter for use in adaptive rate pacing in conjunction with a cardiac rhythm management system for a heart. The maximum pacing rate limiter may function to measure an interval, termed the ERT interval, between a paced ventricular evoked response and a T-wave. The maximum pacing rate limiter may further function to maintain the ERT interval at less than a certain percentage of the total cardiac cycle. In one disclosed embodiment, a maximum pacing rate limiter calculates an ERT rate based on the detected paced ventricular evoked response and the T-wave, and the pacing rate limiter module further communicates the minimum of the ERT rate and an adaptive-rate sensor indicated rate to a pacemaker.
摘要:
Methods and systems for classifying cardiac responses to pacing stimulation and/or preventing retrograde cardiac conduction are described. Following delivery of a pacing pulse to an atrium of the patient's heart during a cardiac cycle, the system senses in the atrium for a retrograde P-wave. The system classifies the atrial response to the pacing pulse based on detection of the retrograde P-wave. The system may also sense for an atrial evoked response and utilize the atrial evoked response in classifying the cardiac pacing response.
摘要:
Methods and systems for classifying cardiac responses to pacing stimulation and/or preventing retrograde cardiac conduction are described. Following delivery of a pacing pulse to an atrium of the patient's heart during a cardiac cycle, the system senses in the atrium for a retrograde P-wave. The system classifies the atrial response to the pacing pulse based on detection of the retrograde P-wave. The system may also sense for an atrial evoked response and utilize the atrial evoked response in classifying the cardiac pacing response. If capture is not detected, the system may deliver additional atrial pacing pulses to reduce atrial retrograde conduction. A backup pace may be delivered to prevent the atrial retrograde conduction if an atrial evoked response is not detected during a cardiac cycle. Alternatively, retrograde management may involve delaying a next scheduled pace may be until expiration of an atrial effective refractory period.