Abstract: A method and device for detecting cardiac signals in a medical device that includes decomposing sensed cardiac signals using a wavelet function to form a corresponding wavelet transform, generating a first wavelet representation corresponding to the wavelet transform that is responsive to RR intervals of the sensed cardiac signals, generating a second wavelet representation that is not responsive to RR intervals associated with the sensed cardiac signals, and determining a device failure in response to the first wavelet representation and the second wavelet representation. The method and device may also include decomposing sensed cardiac signals using a wavelet function to form a corresponding wavelet transform, generating a wavelet representation that is not responsive to RR intervals of the sensed cardiac signals, determining RR intervals associated with the sensed cardiac signals, and determining a device failure in response to the first wavelet representation and the determined RR intervals.

Abstract: A medical device capable of delivering automatic rate-adjusting pacing therapies is provided having an adjustable upper rate limit responsive to an indication of myocardial irritability. The device, which may be embodied as a pacemaker, a pacemaker/cardioverter/defibrillator, or the like, responds to the detection of an arrhythmia as an indicator of myocardial irritability by adjusting an upper rate limit. The adjusted upper rate limit is applied as the maximum allowable pacing rate during delivery of any pacing therapies previously defined as “long-term” pacing therapies.

Abstract: A medical device and associated method for detecting arrhythmias that includes sensing cardiac electrical signals and cardiac hemodynamic signals, determining a long-term baseline hemodynamic measurement in response to a plurality of the sensed cardiac hemodynaic signals, detecting a period of increased metabolic demand in response to the sensed cardiac electrical signals, determining a sinus tachycardia baseline hemodynamic measurement in response sensing of cardiac hemododynamic signals during the detected period of increased metabolic demand, and detecting the arrhythmia and delivering therapy in response to one of only the sensed cardiac electrical signals and the sensed cardiac electrical signals in combination with one or both of the determined long-term baseline hemodynamic measurement and the sinus tachycardia baseline hemodynamic measurement

Abstract: A medical device and associated method for detecting arrhythmias that includes electrodes for sensing cardiac electrical signals and a hemodynamic sensor for sensing a hemodynamic signal. An episode of cardiac electrical event intervals meeting cardiac arrhythmia detection criteria is detected from the sensed electrical signals. Cardiac mechanical events and/or cardiac mechanical event intervals are measured from the hemodynamic signal and used to withhold or confirm a cardiac arrhythmia detection of the episode.

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: 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. The processor determines whether a return cycle length generated subsequent to the delivery of a first plurality of pacing pulses is less than or equal to a cycle length associated with the tachycardia event, and adjusts delivery of a second plurality of pacing pulses in response to the return cycle length being less than or equal to the cycle length associated with the tachycardia event.

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. The processor determines adjustments to the delivered therapy, the adjustments being linearly dependent on characteristics of the tachycardia event.

Abstract: A method and device for detecting cardiac signals in a medical device that includes decomposing sensed cardiac signals using a wavelet function to form a corresponding wavelet transform, generating a first wavelet representation corresponding to the wavelet transform that is responsive to RR intervals of the sensed cardiac signals, generating a second wavelet representation that is not responsive to RR intervals associated with the sensed cardiac signals, determining a no lead failure zone in response to the first wavelet representation and the second wavelet representation, and distinguishing the cardiac event from a device failure in response to the determined no lead failure zone.

Abstract: A medical device and associated method classify a tachycardia according to a site of origin of the tachycardia. Cardiac signals are sensed and a tachycardia event is detected in response to the sensed cardiac signals. Pacing pulses are delivered and a time interval corresponding to a distance traversed by a depolarization associated with the last one of the pacing pulses from a site of delivery of the plurality of pacing pulses is determined. The tachycardia event is classified according to a site of origin in response to the determined time interval.

Abstract: A medical device and associated method discriminate near-field and far-field events by sensing a bipolar signal and a unipolar signal at a tissue site, detecting an event in response to one of the bipolar and unipolar signals, and comparing an event feature determined from the bipolar signal to an event feature determined from the unipolar signal.

Abstract: A cardiac medical device and associated method control delivery of anti-tachycardia pacing (ATP) in response to detecting tachycardia. In one embodiment, an initial set of single chamber pacing pulses are delivered in a single one of the atrium and the ventricle, the other one of the atrium and the ventricle being a non-paced chamber during the initial set of single chamber pacing pulses. The device detects simultaneity between a sensed event in the non-paced chamber and one of the single chamber pacing pulses and delivers ATP in both the atrium and the ventricle in response to detecting the simultaneity.

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. The processor determines whether a return cycle length generated subsequent to the delivery of the first plurality of pacing pulses is greater than or equal to a sum of a cycle length associated with the tachycardia event and a total prematurity associated with the first plurality of pacing pulses, and adjusts delivery of a second plurality of pacing pulses in response to the return cycle length being greater than or equal to a sum of a cycle length associated with the tachycardia event and a total prematurity associated with the first plurality of pacing pulses.

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. The processor determines a cause of the delivered first plurality of pacing pulses failing to terminate the tachycardia event as a result of one of a failure to capture the tachycardia event, a failure to complete peelback, and a failure to entrain a reentrant circuit associated with the tachycardia event, and adjusts delivery of a second plurality of pacing pulses subsequent to the delivery of the first plurality of pacing pulses in response to the determined cause.

Abstract: Ventricular arrhythmias are monitored and classified based upon various criteria. One criterion is PR dissociation which is determined by comparing the PR interval in a current RR cycle to a median PR value. If the current PR interval varies too far from the median, then dissociation is indicated. Often, there are multiple atrial events in a given RR interval and the PR value has been based upon the last atrial event in the cycle. An algorithm determines whether to use the last atrial event in a cycle or whether an earlier atrial event occurred and would provide a more accurate PR value.

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: A cardiac medical device used for delivering anti-tachycardia pacing in both the atrial and ventricular regions in a simultaneous manner, while preventing potential of inducing atrial arrhythmia. The pacing pulses may be synchronized in a gradual manner so that simultaneous delivery of the pulses is ultimately achieved at reduced risk of inducing atria arrhythmia. The pacing pulses may also be synchronized immediately after a determination is made whether simultaneous pacing purses will be delivered in the vulnerable regions of the cardiac cycle.

Abstract: A troubleshooting method can identify potential sources of noise emanating from an implanted portion of a medical system. The method, which may be carried out by the system, for example, according to pre-programmed instructions, includes a step of collecting at least one EGM sample from a sensing pair of electrodes, and an EGM sample from each of a plurality of recording pairs of electrodes. The sensing pair may be formed by first and second electrodes of an implanted lead, and the plurality of recording pairs include pairs formed by each of the lead electrodes and an electrode of an implanted device. Following collection, the EGM samples from the recording pairs may be analyzed for the presence or absence of noise and, then, potential noise sources may be determined.

Abstract: A cardiac medical device used for delivering anti-tachycardia pacing in both the atrial and ventricular regions in a simultaneous manner, while preventing potential of inducing atrial arrhythmia. The pacing pulses may be synchronized in a gradual manner so that simultaneous delivery of the pulses is ultimately achieved at reduced risk of inducing atria arrhythmia. The pacing pulses may also be synchronized immediately after a determination is made whether simultaneous pacing purses will be delivered in the vulnerable regions of the cardiac cycle.

Abstract: Ventricular arrhythmias are monitored and classified based upon various criteria. One criterion is PR dissociation which is determined by comparing the PR interval in a current RR cycle to a median PR value. If the current PR interval varies too far from the median, then dissociation is indicated. Often, there are multiple atrial events in a given RR interval and the PR value has been based upon the last atrial event in the cycle. An algorithm determines whether to use the last atrial event in a cycle or whether an earlier atrial event occurred and would provide a more accurate PR value.

Abstract: A troubleshooting method can identify potential sources of noise emanating from an implanted portion of a medical system. The method, which may be carried out by the system, for example, according to pre-programmed instructions, includes a step of collecting at least one EGM sample from a sensing pair of electrodes, and an EGM sample from each of a plurality of recording pairs of electrodes. The sensing pair may be formed by first and second electrodes of an implanted lead, and the plurality of recording pairs include pairs formed by each of the lead electrodes and an electrode of an implanted device. Following collection, the EGM samples from the recording pairs may be analyzed for the presence or absence of noise and, then, potential noise sources may be determined.