摘要:
A system and method for performing independent, off-line evaluation of event sensing for collected electrograms, comprising: sensing an electrogram using an implantable medical device (IMD); determining locations of heart beats on at least one channel of the electrogram using a multi-pass process, resulting in a group of multi-pass beat locations; storing the electrogram and device-identified beat locations in a memory location; and retrieving the electrogram and device-identified beat locations from the memory location. The multi-pass process determines locations of heart beats on at least a first channel of the electrogram. The device-identified group of beat locations are then compared to the multi-pass group of beat locations identified using the multi-pass method. Based on the comparing step, oversensing of beats, undersensing of beats, or noise from the device can be detected.
摘要:
Methods and systems for selecting tachyarrhythmia therapy based on the morphological organization level of the arrhythmia are described. Morphological organization levels of arrhythmias are associated with cardiac therapies. The morphological organization levels are related to cardiac signal morphologies of the arrhythmias. An arrhythmia episode is detected and the morphological organization level of the arrhythmia episode is determined. A cardiac therapy associated with the morphological organization level of the arrhythmia episode is delivered to treat the arrhythmia. For example, the morphological organization levels may be associated with the cardiac therapies based on one or more of retrospective database analysis, patient therapy tolerance, and physician input. The associations may be static or may be dynamically adjusted based on therapy efficacy.
摘要:
Cardiac treatment methods and devices provide for templates representative of past tachyarrhythmia events, each template associated with a therapy. Methods involve providing a cardiac waveform representative of a patient's cardiac activity and identifying a portion that indicates an arrhythmic event. A cardiac template corresponding to the portion is generated, and a therapy is associated with the template useful for treating a subsequent arrhythmia. The waveform portion may be identified by a physician using a patient-external device to display the cardiac waveform. The template may be generated by a physician selecting the cardiac waveform, and determining if the therapy associated with the template was satisfactory and/or effective in treating the arrhythmia. Identification may involve matching the event to templates generated using cardiac waveforms other than the patient's cardiac waveforms. The template may be generated in a patient-internal or patient-external medical device such as a programmer, and/or an advanced patient management system.
摘要:
A system and method for performing off-line analysis of cardiac electrogram data, comprising: retrieving an electrogram from a memory location; identifying a first-channel group of candidate beats from at least a first channel of the electrogram; and identifying a second-channel group of candidate beats from at least a second channel of an electrogram. For each first-channel beat candidate near a second-channel beat candidate, the amplitude of the first-channel beat candidate is compared with the amplitude of a previous beat and the amplitude of a next beat on the first electrogram channel, and first-channel beat candidates that are outside of a first pre-determined range from either the previous or next beat are removed. Then first-channel beat candidates that are outside of a second pre-determined range from either the previous or next beat candidate are removed.
摘要:
An indication of an actual or potential heart failure condition is computed. One example includes monitoring a first heart rate preceding a first onset of a first sinus tachyarrhythmia episode. Upon detecting the first sinus tachyarrhythmia episode, the indication is automatically provided using information about the first heart rate and how quickly the first onset occurs.
摘要:
A system and method for performing off-line analysis of cardiac electrogram data, comprising: retrieving an electrogram from a memory location; identifying a first-channel group of candidate beats from at least a first channel of the electrogram; and identifying a second-channel group of candidate beats from at least a second channel of an electrogram. For each first-channel beat candidate near a second-channel beat candidate, the amplitude of the first-channel beat candidate is compared with the amplitude of a previous beat and the amplitude of a next beat on the first electrogram channel, and first-channel beat candidates that are outside of a first pre-determined range from either the previous or next beat are removed. Then first-channel beat candidates that are outside of a second pre-determined range from either the previous or next beat candidate are removed.
摘要:
A method comprises detecting at least one episode of ventricular tachyarrhythmia in a subject using an implantable medical device (IMD), sensing at least one heart sound signal for the subject using the IMD, the heart sound signal associated with mechanical vibration of a heart of the subject; initiating, in response to and during the detected episode of tachyarrhythmia, a measurement of hemodynamic stability of the ventricular tachyarrhythmia from the heart sound signal, and deeming whether the ventricular tachyarrhythmia is stable according to the measurement of hemodynamic stability. The measurement of hemodynamic stability is determined using linear prediction.
摘要:
Detecting or validating signals such as cardiac beats can be performed in the presence of myopotential or other noise. An amplitude peak, which can be a candidate for a detected beat, can be used in a normalized or other weighted average, along with a preceding and subsequent sample. The weighted average is compared to a noise threshold. Based on the result, the amplitude peak is either deemed an actual beat (e.g., depolarization or repolarization), or noise. The described systems, devices, and methods can improve the accuracy of detecting an actual beat in the presence of noise, during normal sinus rhythm or during an arrhythmia such as ventricular fibrillation. This, in turn, improves the accuracy with which therapy is delivered or withheld by an implantable device.
摘要:
A single-pass endocardial lead electrode adapted for implantation on or about the heart and for connection to a system for monitoring or stimulating cardiac activity includes a lead body with a circumferential outer surface. The lead includes a first distal end electrode which has a first electrical conducting surface. The lead body also has a second electrode which has a second electrical conducting surface. The second electrode is adapted for positioning and fixation to the wall of the atrium of the heart. A passive fixation element may be used as part of the second electrode. The lead body also includes a curved portion which facilitates the positioning and passive fixation of the second electrode.
摘要:
Methods and systems for selecting tachyarrhythmia therapy based on the morphological organization level of the arrhythmia are described. Morphological organization levels of arrhythmias are associated with cardiac therapies. The morphological organization levels are related to cardiac signal morphologies of the arrhythmias. An arrhythmia episode is detected and the morphological organization level of the arrhythmia episode is determined. A cardiac therapy associated with the morphological organization level of the arrhythmia episode is delivered to treat the arrhythmia. For example, the morphological organization levels may be associated with the cardiac therapies based on one or more of retrospective database analysis, patient therapy tolerance, and physician input. The associations may be static or may be dynamically adjusted based on therapy efficacy.