Abstract: The efficacy of cardiac resynchronization therapy applied to a patient's heart by an implantable device are improved by obtaining acute hemodynamic feedback during implantation of a pacing device. A first and a second transducer are temporarily placed proximate to a portion of the patient's heart during device implant, and a distance between the transducers is monitored as the therapy is applied. A parameter (e.g. lead location, biventricular pacing, pacing rate, or the like) of the cardiac therapy is adjusted in response to the distance between the transducers until a desired result is obtained, after which the first and second transducers can be removed from the patient.

Abstract: A method and system for detecting T-wave alternans for use in an implanted medical device uses wave transformation of QT intervals to obtain a reliable measure of TWA. In one embodiment, an array provides alternating sign multiplication factors which are applied respectively to n consecutive QT values. Each successive QT value is high pass filtered and moved sequentially through a queue so that each cycle each of the n QT values is multiplied by one of the factors; the products are summed and made absolute to provide an alternans match value. The alternans match is compared with a noise threshold signal, and alternans is declared when the match exceeds the threshold by a predetermined amount. The array is programmable and can be varied, providing a high degree of flexibility to optimize the test for the patient.

Abstract: An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. Improved ventricular sensing, detection and classification is provided.

Abstract: Determining an optimal atrioventricular interval is of interest for proper delivery of cardiac resynchronization therapy. Although device optimization is gradually and more frequently being performed through a referral process with which the patient undergoes an echocardiographic optimization, the decision of whether to optimize or not is still generally reserved for the implanting physician. Recent abstracts have suggested a formulaic approach for setting A-V interval based on intrinsic electrical sensing, that may possess considerable appeal to clinicians versus a patient average nominal A-V setting of 100 ms. The present invention presents a methods of setting nominal device settings based on entering patient cardiac demographics to determine what A-V setting may be appropriate. The data is based on retrospective analysis of the MIRACLE trial to determine what major factors determined baseline A-V settings.

Abstract: An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. Improved ventricular sensing, detection and classification is provided.

Abstract: 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.

Abstract: A system and method for cardiovascular analysis includes an implantable medical device capable of generating hemodynamic pressure waveform data based upon sensed pressure. Hemodynamic waveform data is analyzed to identify artifactual data represented in the hemodynamic waveform.

Abstract: A method and device for generating a template that includes identifying events of a plurality of sensed events having predetermined characteristics as first selected events and generating the template from the first selected events. Events of the plurality of events having the predetermined characteristics are identified as second selected events, and a determination is made as to whether the template is valid in response to the second selected events. The template is updated from the second selected events in response to the template not being valid.

Abstract: Automated adjustment of a pre-excitation interval (PEI) used to deliver hemodynamically efficient fusion pacing therapy.

Abstract: An implantable medical device (IMD) identifies lead performance issues and provides alternative lead configurations to continue with the programmed therapy. In the absence of an appropriate alternatively lead configuration, the IMD determines alternative mechanisms to provide a similar therapy or to determine a secondary therapy.

Abstract: An implantable medical device (IMD) includes a detector for detecting the presence of x-ray radiation, where the presence of x-ray radiation is detected in response to the strength of the x-ray radiation exceeding a first threshold. In one embodiment, the IMD includes a processor for adjusting a cardiac stimulation rate IMD in response to determining that the strength of the detected x-ray radiation exceeds a second threshold. The second pre-selected x-ray radiation threshold is greater than the first pre-selected x-ray radiation threshold. In another embodiment, the implantable device includes a detector for detecting the presence of any amount x-ray radiation and a processor for adjusting a stimulation rate provided by the IMD in response to detected x-ray radiation to reduce the chance of over-sampling artifacts or inappropriate therapy delivery.

Abstract: An electro-stimulation device includes a pair of electrodes for connection to at least one location in the body that affects or regulates the heartbeat. The electro-stimulation device both electrically arrests the heartbeat and stimulates the heartbeat. A pair of electrodes are provided for connection to at least one location in the body that affects or regulates the heartbeat. The pair of electrodes may be connected to an intravenous catheter for transvenous stimulation of the appropriate nerve. In another aspect, the invention is directed to a method for arresting the beat of a heart in a living body comprising the steps of connecting the pair of electrodes to at least one location in the body that affects or regulates the heartbeat and supplying an electrical current to the electrodes of sufficient amplitude and duration to arrest the heartbeat.

Abstract: A pacing control is used in a multiple-chamber cardiac pacing system, which, upon detecting an atrial arrhythmia, automatically switches to a special therapy mode and administers a selected anti-tachycardia pacing (ATP) therapy in the atrium, and which switches to a standard pacing mode following delivery of the ATP therapy. The pacing control adjusts the timing of pacing pulses to be delivered to the atrium and/or the ventricle to minimize any potential ventricular pauses that may result from the switch from the therapy mode to the standard pacing mode.

Abstract: A medical device for implantation within a patient comprising a lead body including a conductor within the lead body and a transducer supported by the lead body. The conductor is electrically coupled to the transducer by a conductive fluid, paste or gel. The conductive fluid, paste or gel may be contained within a well in the lead body. The transducer may be a MEMS chip and/or an integrated circuit and may perform any of a variety of functions such as sensing physiological data.

Abstract: An implantable medical device system senses a first signal using a first acoustical sensor adapted to be operatively positioned in a first internal body location for sensing heart sounds in a patient. The system includes a second acoustical sensor adapted to be operatively positioned in a second internal body location for sensing sounds in the patient and generate a second signal that is less responsive to the heart sounds than the first acoustical signal. An implantable medical device including a housing and a processor enclosed in the housing receives the first signal and the second signal and generates a corrected first signal by canceling non-cardiac signals in the first signal using the second signal.

Abstract: A method and device for delivering anti-tachycardia pacing (ATP) therapy that includes an electrode to sense cardiac signals and to deliver the therapy, sensing circuitry, electrically coupled to the electrode, to detect the tachycardia event in response to the sensed cardiac signals, and a processor to control delivery of the therapy.

Abstract: SubQ ICDs are disclosed that are entirely implantable subcutaneously with minimal surgical intrusion into the body of the patient and provide distributed cardioversion-defibrillation sense and stimulation electrodes for delivery of cardioversion-defibrillation shock and pacing therapies across the heart when necessary. Configurations include one hermetically sealed housing with 1 or, optionally, 2 subcutaneous sensing and cardioversion-defibrillation therapy delivery leads or alternatively, 2 hermetically sealed housings interconnected by a power/signal cable. The housings are generally dynamically configurable to adjust to varying rib structure and associated articulation of the thoracic cavity and muscles. Further the housings may optionally be flexibly adjusted for ease of implant and patient comfort.

Abstract: The invention provides methods and apparatus for determining in a non-tracking pacing mode (e.g., DDI/R, VVI/R) whether a ventricular pacing stimulus is capturing a paced ventricle, including some or all of the following aspects. For example, increasing a ventricular pacing rate a nominal amount to an overdrive pacing rate higher than a most recent heart rate and evaluating a conduction interval from a first pacing ventricle to a second sensing ventricle and then continuing to monitor the underlying rate to ensure that a threshold testing pacing rate will not exceed a predetermined minimum interval and providing pacing stimulation to the first ventricle and sensing the second ventricle to determine whether the pacing stimulation to the first ventricle was one of sub-threshold and supra-threshold. The methods and apparatus are especially useful in conjunction with ensuring actual delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or “CRT”).

Abstract: According to the present invention at least a pair of neurological stimulation electrodes are disposed in, on, about, adjacent and/or within excitable neural tissue of a subject. Cardiac activity of a patient is detected using one or more electrodes adapted for delivery of a neurological stimulation therapy (NST). Following detection of certain types of cardiac activity one or more of the plurality of stimulation electrodes deliver or withhold NST, if desired in synchrony with the cardiac activity or in response to the detected cardiac activity. The NST delivered includes without limitation subcutaneous stimulation, peripheral, TENS and/or vagal nerve stimulation therapy or the like.

Abstract: An implantable medical device provides ventricular pacing capabilities and optimizes AV intervals for multiple purposes. In general, intrinsic conduction is promoted by determining when electromechanical systole (EMS) ends and setting an AV interval accordingly. EMS is determined utilizing various data including QT interval, sensor input, and algorithmic calculations.