47 results about "Pacing interval" patented technology

The present invention relates to monitoring septal wall motion of the atrial and / or ventricular chambers of a heart for optimizing cardiac pacing intervals based on signals derived from the monitored wall motion. At least one lead of medical device is equipped with a motion sensor adapted to couple to septal tissue. The device receives and may post-process (e.g., suitably filter, rectify and / or integrate) motion signals to determine acceleration, velocity and / or displacement. During pacing interval optimization the wall motion is measured for those pacing intervals and the pacing interval setting(s) that produce minimal wall motion for chronic therapy delivery. In addition, methods for periodically determining whether to cease or resume delivery of a bi-ventricular pacing therapy to a patient that may have experienced beneficial reverse remodeling of the heart.

Methods and devices for determining optimal Atrial to Ventricular (AV) pacing intervals and Ventricular to Ventricular (VV) delay intervals in order to optimize cardiac output. Impedance, preferably sub-threshold impedance, is measured across the heart at selected cardiac cycle times as a measure of chamber expansion or contraction. One embodiment measures impedance over a long AV interval to obtain the minimum impedance, indicative of maximum ventricular expansion, in order to set the AV interval. Another embodiment measures impedance change over a cycle and varies the AV pace interval in a binary search to converge on the AV interval causing maximum impedance change indicative of maximum ventricular output. Another method varies the right ventricle to left ventricle (VV) interval to converge on an impedance maximum indicative of minimum cardiac volume at end systole. Another embodiment varies the VV interval to maximize impedance change.

A signal indicative of cardiac contractions of a patient's heart is produced, as the patient's heart is paced using different sets of pacing interval parameters. Measures of pulse amplitude are obtained from the signal. Pacing interval optimization is performed based on the measures of pulse amplitude.

A system and method for monitoring left ventricular (LV) lateral wall motion and for optimizing cardiac pacing intervals based on left ventricular lateral wall motion is 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 a motion sensor electromechanically coupled to the lateral wall of the left ventricle. The device receives and processes wall motion sensor signals to determine a signal characteristic indicative of systolic LV lateral wall motion or acceleration. An automatic pacing interval optimization method evaluates the LV lateral wall motion during varying pacing interval settings, including atrial-ventricular intervals and inter-ventricular intervals and selects the pacing interval setting(s) that correspond to LV lateral wall motion associated with improved cardiac synchrony and hemodynamic performance.

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.

Methods and systems are disclosed that characterize cardiac function using an acceleration sensor to acquire and analyze the frequency dynamics associated with the isovolumic contraction phase (“ICP”). This information can be used to characterize heart function; optimize therapy for cardiomyopathy, including CRT therapy (including pacing intervals and required pharmacologic therapy); and to optimize CCM therapy. In addition, this information can be used to identify target pacing regions for CRT lead placement. Further, analyzing the frequency dynamics can be used to characterize pathologic heart vibrational motion, such as mitral regurgitation and the third or fourth heart sound, and the response of this motion to therapy for cardiomyopathy.

A hemodynamic status of a patient is determined in an implanted medical device (IMD) by observing a perturbation of the patient's heart, measuring heart rate turbulence resulting from the perturbation, and quantifying the heart rate turbulence to determine the hemodynamic status. The perturbation may be naturally-occurring, or may be generated by the implantable medical device. The patient's response to heart rate turbulence may also be used to provide a response to the patient, such as providing an alarm and / or administering a therapy. Heart rate turbulence may also be used to tune and / or optimize a device parameter such as A-V or V—V pacing intervals.

Systems and methods for pacing the heart using resynchronization pacing delays that achieve improvement of cardiac function are described. An early activation pacing interval is calculated based on an optimal AV delay and an atrial to early ventricular activation interval between an atrial event and early activation of a ventricular depolarization. The early activation pacing interval for the ventricle is calculated by subtracting the measured AVEA from the calculated optimal AV delay. The early activation pacing interval is initiated responsive to sensing early activation of the ventricle and pacing is delivered relative to expiration of the early activation pacing interval.

Methods and devices for determining optimal Atrial to Ventricular (AV) pacing intervals and Ventricular to Ventricular (VV) delay intervals in order to optimize cardiac output. Impedance, preferably sub-threshold impedance, is measured across the heart at selected cardiac cycle times as a measure of chamber expansion or contraction. One embodiment measures impedance over a long AV interval to obtain the minimum impedance, indicative of maximum ventricular expansion, in order to set the AV interval. Another embodiment measures impedance change over a cycle and varies the AV pace interval in a binary search to converge on the AV interval causing maximum impedance change indicative of maximum ventricular output. Another method varies the right ventricle to left ventricle (VV) interval to converge on an impedance maximum indicative of minimum cardiac volume at end systole. Another embodiment varies the VV interval to maximize impedance change.

Impedance, e.g. sub-threshold impedance, is measured across the heart at selected cardiac cycle times as a measure of chamber expansion or contraction. One embodiment measures impedance over a long AV interval to obtain the minimum impedance, indicative of maximum ventricular expansion, in order to set the AV interval. Another embodiment measures impedance change over a cycle and varies the AV pace interval in a binary search to converge on the AV interval causing maximum impedance change indicative of maximum ventricular output. Another method varies the right ventricle to left ventricle (VV) interval to converge on an impedance maximum indicative of minimum cardiac volume at end systole. Another embodiment varies the VV interval to maximize impedance change. Other methods vary the AA interval to maximize impedance change over the entire cardiac cycle or during the atrial cycle.

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.

Methods and devices for determining optimal Atrial to Ventricular (AV) pacing intervals and Ventricular to Ventricular (VV) delay intervals in order to optimize cardiac output. Impedance, preferably sub-threshold impedance, is measured across the heart at selected cardiac cycle times as a measure of chamber expansion or contraction. One embodiment measures impedance over a long AV interval to obtain the minimum impedance, indicative of maximum ventricular expansion, in order to set the AV interval. Another embodiment measures impedance change over a cycle and varies the AV pace interval in a binary search to converge on the AV interval causing maximum impedance change indicative of maximum ventricular output. Another method varies the right ventricle to left ventricle (VV) interval to converge on an impedance maximum indicative of minimum cardiac volume at end systole. Another embodiment varies the VV interval to maximize impedance change.

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.

A system and method for an implantable cardiac pacing device provide for delivery of anti-tachycardia pacing of the atrium upon detection of atrial tachycardia combined with automatic re-synchronization of ventricular pacing directly following the last atrial pulse of the anti-tachycardia scheme. At the onset of delivery of the ATP train or like scheme of ATP, an appropriate ventricular pacing interval is calculated to enable asynchronous pacing of the ventricle during the ATP and synchronous delivery of the next ventricular pulse at a delay following the end of the ATP train. Upon determination of AT, an algorithm is used to calculate if a ventricular pacing interval can be found that meets maximum and minimum pacing criteria and also provides that the next ventricular pace pulse following the end of the ATP train will follow the last atrial pulse of the train by a suitable AV delay. If such a suitable pacing interval is found, the ventricular pacing interval is set to a temporary value and the train is delivered. If such a pacing interval cannot be initially determined the system waits for one more atrial sense and then repeats the determination to find such a suitable ventricular pacing interval.

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.

A method for processing a biopotential signal includes detecting a pacing signal, and applying a dynamic filter on a pacing channel based on the detected pacing signal. A method for processing a biopotential signal includes detecting a pacing signal, and automatically obtaining a post-pacing interval based at least in part on the pacing signal.