摘要:
A method and device for delivering pre-excitation pacing to prevent or reduce cardiac remodeling following a myocardial infarction is described. The pre-excitation pacing is modulated in accordance with an intravascular pressure measurement in order to balance the beneficial effects of stress reduction with hemodynamic compromise.
摘要:
A cardiac rhythm management (CRM) system provides for post-myocardial infarction (MI) therapy with closed-loop control using one or more ultrasound transducers sensing one or more ultrasound signals indicative of cardiac dimensions. Cardiac size parameters are produced using the one or more ultrasound signals to represent, for example, cardiac chamber diameter, cardiac chamber volume, cardiac wall thickness, infarct size, and degree of change in any of these parameters over time or between measurements. In various embodiments, such cardiac size parameters provide for titration, safety check, and acute optimization of the post-MI therapy.
摘要:
A cardiac rhythm management system is capable of treating irregular ventricular heart contractions, such as during atrial tachyarrhythmias such as atrial fibrillation. A first indicated pacing interval is computed based at least partially on a most recent V—V interval duration between ventricular beats and a previous value of the first indicated pacing interval. Pacing therapy is provided based on either the first indicated pacing interval or also based on a second indicated pacing interval, such as a sensor-indicated pacing interval. A weighted averager such as an infinite impulse response (IIR) filter adjusts the first indicated pacing interval for sensed beats and differently adjusts the first indicated pacing interval for paced beats. The system regularizes ventricular rhythms by pacing the ventricle, but inhibits pacing when the ventricular rhythms are stable.
摘要:
A cardiac rhythm management system includes atrial shock timing optimization. Because an atrial tachyarrhythmia, such as atrial fibrillation typically causes significant variability in the ventricular heart rate, resulting in potentially proarrhythmic conditions. The system avoids delivering atrial cardioversion/defibrillation therapy during potentially proarrhythmic conditions because doing so could result in dangerous ventricular arrhythmias. Using Ventricular Rate Regularization (“VRR”) techniques, the system actively stabilizes the ventricular heart rate to obtain less potentially proarrhythmic conditions for delivering the atrial tachyarrhythmia therapy. The intrinsic ventricular heart rate is stabilized at a variable VRR-indicated rate, computed using an infinite impulse response (IIR) filter, and based on the underlying intrinsic ventricular heart rate. The system withholds delivery of atrial cardioversion/defibrillation therapy until the intervals between ventricular beats (“V-V intervals”) meet certain criteria that decrease the chance that the atrial cardioversion/defibrillation therapy will induce a ventricular arrhythmia.
摘要:
A cardiac rhythm management system includes techniques for computing an indicated pacing interval, AV delay, or other timing interval. In one embodiment, a variable indicated pacing interval is computed based at least in part on an underlying intrinsic heart rate. The indicated pacing interval is used to time the delivery of biventricular coordination therapy even when ventricular heart rates are irregular, such as in the presence of atrial fibrillation. In another embodiment, a variable filter indicated AV interval is computed based at least in part on an underlying intrinsic AV interval. The indicated AV interval is used to time the delivery of atrial tracking biventricular coordination therapy when atrial heart rhythms are not arrhythmic. Other indicated timing intervals may be similarly determined. The indicated pacing interval, AV delay, or other timing interval can also be used in combination with a sensor indicated rate indicator.
摘要:
Methods and systems are directed to delivering cardiac pacing therapy to a patient. A pacing therapy associated with one or more pacing parameters is delivered. Alternate cardiac pacing therapies associated with one or more alternate pacing parameters are transitioned to, based on a sleep/wake cycle of the patient. Interactions between the pacing parameters of the pacing therapy and the alternate pacing parameters are resolved. Resolving pacing parameters may be based on analysis of lower rate limits and/or lower rate hysteresis, for example.
摘要:
Methods and systems are directed to delivering cardiac pacing therapy to a patient. A pacing therapy associated with one or more pacing parameters is delivered. Alternate cardiac pacing therapies associated with one or more alternate pacing parameters are transitioned to, based on a sleep/wake cycle of the patient. Interactions between the pacing parameters of the pacing therapy and the alternate pacing parameters are resolved. Resolving pacing parameters may be based on analysis of lower rate limits and/or lower rate hysteresis.
摘要:
Systems and methods provide for determining blood gas saturation based on one or more measured respiration parameters. A parameter of respiration is measured implantably over a duration of time. The measured respiratory parameter is associated with a blood gas saturation level. Blood gas saturation is determined based on the measured respiration parameter. At least one of associating the measured respiratory parameter and determining blood gas saturation is preferably preformed implantably.
摘要:
Devices and methods for detecting disordered breathing involve determining that the patient is asleep and sensing one or more signals associated with disordered breathing indicative of sleep-disordered breathing while the patient is asleep. Sleep-disordered breathing is detected using the sensed signals associated with disordered breathing. The sensed signals associated with disordered breathing may also be used to acquire a respiration pattern of one or more respiration cycles. Characteristics of the respiration pattern are determined. The respiration pattern is classified as a disordered breathing episode based on the characteristics of the respiration pattern. One or more processes involved in the detection of disordered breathing are performed using an implantable device.
摘要:
Disordered breathing events may be classified as central, obstructive or a combination of central an obstructive in origin based on patient motion associated with respiratory effort. Central disordered breathing is associated with disrupted respiration with reduced respiratory effort. Obstructive disordered breathing is associated with disrupted respiration accompanied by respiratory effort. A disordered breathing classification system includes a disordered breathing detector and a respiratory effort motion sensor. Components of the disordered breathing classification system may be fully or partially implantable.