摘要:
Provided herewith are methods and apparatus for optimizing an atrioventricular (AV) pacing delay interval based upon ECG-based optimization is calculated as a linear function of P-wave duration, sensed PR (intrinsic) interval, sensed or paced QRS duration and heart rate. Since the relationship among these parameters is linear, once the coefficients are solved (which can be any value, including null) with reference to a known optimized AV interval (AVopt) such as from an echocardiographic study, an AVopt value can be dynamically adjusted in an ambulatory subject. The various combinations of values can be loaded into a look up table or calculated automatically. And, since some of the parameters do not typically change much over time they can be determined acutely and fed into the equation while the other values can be measured frequently. The parameter values can be measured by an implantable medical device such as a dual- or triple-chamber pacemaker.
摘要:
The disclosure provides methods and apparatus of left ventricular pacing including automated adjustment of a atrio-ventricular (AV) pacing delay interval and intrinsic AV nodal conduction testing. It includes—upon expiration or reset of a programmable AV Evaluation Interval (AVEI)—performing the following: temporarily increasing a paced AV interval and a sensed AV interval and testing for adequate AV conduction and measuring an intrinsic atrio-ventricular (PR) interval for a right ventricular (RV) chamber. Thus, in the event that the AV conduction test reveals a physiologically acceptable intrinsic PR interval then storing the physiologically acceptable PR interval in a memory structure (e.g., a median P-R from one or more cardiac cycles). In the event that the AV conduction test reveals an AV conduction block condition or if unacceptably long PR intervals are revealed then a pacing mode-switch to a bi-ventricular (Bi-V) pacing mode occurs and the magnitude of the AVEI is increased.
摘要:
Delivery of fusion pacing therapy to a later depolarizing ventricle (V2) of a heart of a patient may be timed based on the depolarization of the V2 during at least one prior cardiac cycle. In some examples, a V2 pacing pulse is delivered upon the expiration of a pacing interval that begins at detection of an atrial sense or pace event (AP/S). The pacing interval may be substantially equal to the duration of time between an AP/S and a V2 sensing event of at least one prior cardiac cycle decremented by an adjusted pre-excitation interval (PEI). In another example, the V2 pacing pulse is delivered at the expiration of a pacing interval that begins upon detection of a V2 sensing event of a prior cardiac cycle. The pacing interval may be substantially equal to a duration of time at least two subsequent V2 sensing events decremented by the adjusted PEI.
摘要:
Cardiac resynchronization therapy (CRT) delivered to a heart of a patient may be adjusted based on detection of a surrogate indication of the intrinsic atrioventricular conduction of the heart. In some examples, the surrogate indication is determined to be a sense event of the first depolarizing ventricle of the heart within a predetermined period of time following the delivery of a fusion pacing stimulus to the later depolarizing ventricle. In some examples, the CRT is switched from a fusion pacing configuration to a biventricular pacing configuration if the surrogate indication is not detected, and the CRT is maintained in a fusion pacing configuration if the surrogate indication is detected.
摘要:
Cardiac resynchronization therapy (CRT) delivered to a heart of a patient may be adjusted based on detection of a surrogate indication of the intrinsic atrioventricular conduction of the heart. In some examples, the surrogate indication is determined to be a sense event of the first depolarizing ventricle of the heart within a predetermined period of time following the delivery of a fusion pacing stimulus to the later depolarizing ventricle. In some examples, the CRT is switched from a fusion pacing configuration to a biventricular pacing configuration if the surrogate indication is not detected, and the CRT is maintained in a fusion pacing configuration if the surrogate indication is detected.
摘要:
Methods and apparatus of left ventricular pacing including automated adjustment of a atrio-ventricular (AV) pacing delay interval and intrinsic AV nodal conduction testing. Thus, in the event that the AV conduction test reveals a physiologically acceptable intrinsic PR interval then storing the physiologically acceptable PR interval in a memory structure (e.g., a median P-R from one or more cardiac cycles) and delivering fusion pacing using a decremented value of the intrinsic PR interval.
摘要:
Delivery of fusion pacing therapy to a later depolarizing ventricle (V2) of a heart of a patient may be timed based on the depolarization of the V2 during at least one prior cardiac cycle. In some examples, a V2 pacing pulse is delivered upon the expiration of a pacing interval that begins at detection of an atrial sense or pace event (AP/S). The pacing interval may be substantially equal to the duration of time between an AP/S and a V2 sensing event of at least one prior cardiac cycle decremented by an adjusted pre-excitation interval (PEI). In another example, the V2 pacing pulse is delivered at the expiration of a pacing interval that begins upon detection of a V2 sensing event of a prior cardiac cycle. The pacing interval may be substantially equal to a duration of time at least two subsequent V2 sensing events decremented by the adjusted PEI.
摘要:
Provided herewith are methods and apparatus for optimizing an atrioventricular (AV) pacing delay interval based upon ECG-based optimization is calculated as a linear function of P-wave duration, sensed PR (intrinsic) interval, sensed or paced QRS duration and heart rate. Since the relationship among these parameters is linear, once the coefficients are solved (which can be any value, including null) with reference to a known optimized AV interval (AVopt) such as from an echocardiographic study, an AVopt value can be dynamically adjusted in an ambulatory subject. The various combinations of values can be loaded into a look up table or calculated automatically. And, since some of the parameters do not typically change much over time they can be determined acutely and fed into the equation while the other values can be measured frequently. The parameter values can be measured by an implantable medical device such as a dual- or triple-chamber pacemaker.
摘要:
A medical device and associated method control the delivery of a cardiac pacing therapy including selecting left ventricular pacing sites for delivering the therapy. The left ventricular pacing sites are selected by delivering pacing pulses to a patient's left ventricle at multiple pacing sites one at a time and determining right ventricular activation times in response to the pacing pulses being delivered at each of the pacing sites. A left ventricular pacing site is selected in response to the determined right ventricular activation times.
摘要:
A medical device system and method for delivering mechanically fused left ventricular cardiac stimulation. A sensor monitors left ventricular acceleration while left ventricular cardiac stimulation is provided at an AV interval. The left ventricular acceleration is used to calculate a mechanical response interval and the mechanical response interval is compared to a desired mechanical response interval. The AV interval is adjusted until the mechanical response interval is equal to the desired mechanical response interval.