Abstract: A medical device and method for detecting and classifying cardiac rhythm episodes that includes a sensing module to sense cardiac events; a therapy delivery module, and a detection module configured to determine intervals between the sensed cardiac events, determine a predetermined cardiac episode is occurring in response to the determined intervals, determine whether a ventricular rate is greater than an atrial rate in response to the determined intervals, determine whether oversensing is occurring in response to the ventricular rate being greater than the atrial rate, adjust the determined intervals in response to oversensing occurring to generate an adjusted ventricular rate, determine whether the cardiac episode is occurring in response to the adjusted ventricular rate, perform a supraventricular tachycardia (SVT) discrimination analysis in response to the cardiac episode occurring in response to the adjusted ventricular rate, and control the therapy delivery module to deliver therapy in response to the S

Abstract: A medical device and method for detecting and classifying cardiac rhythm episodes that includes a sensing module to sense cardiac events, a therapy delivery module, and a detection module configured to determine intervals between the sensed cardiac events, determine a predetermined cardiac episode is occurring in response to the determined intervals, determine whether a ventricular rate is greater than an atrial rate in response to the determined intervals, determine whether undersensing is occurring in response to the ventricular rate being greater than the atrial rate, perform a supraventricular tachycardia (SVT) discrimination analysis in response to undersensing occurring, and control the therapy delivery module to deliver therapy in response to the SVT discrimination analysis.

Abstract: A medical device and method for detecting and classifying cardiac rhythm episodes that includes a sensing module to sense cardiac events; a therapy delivery module, and a detection module configured to determine intervals between the sensed cardiac events, determine a predetermined cardiac episode is occurring in response to the determined intervals, determine whether a ventricular rate is greater than an atrial rate in response to the determined intervals, determine whether oversensing is occurring in response to the ventricular rate being greater than the atrial rate, adjust the determined intervals in response to oversensing occurring to generate an adjusted ventricular rate, determine whether the cardiac episode is occurring in response to the adjusted ventricular rate, perform a supraventricular tachycardia (SVT) discrimination analysis in response to the cardiac episode occurring in response to the adjusted ventricular rate, and control the therapy delivery module to deliver therapy in response to the S

Abstract: A medical device and associated method for detecting and treating tachyarrhythmias acquires a cardiac signal using electrodes coupled to a sensing module. Cardiac events are sensed from the cardiac signal and a processing module computes a first morphology metric for each sensed cardiac event occurring during a time segment of the cardiac signal. The first morphology metrics corresponding to an event originating in a ventricular chamber are counted. The first processing module computes a second morphology metric for the time segment of the cardiac signal in response to the count of the first morphology metrics meeting a threshold number of events. The time segment is classified as a shockable segment in response to the second morphology metric meeting a detection criterion.

Abstract: Techniques and systems for monitoring cardiac arrhythmias and delivering electrical stimulation therapy using a subcutaneous implantable cardioverter defibrillator (SICD) and a leadless pacing device (LPD) are described. For example, the SICD may detect a tachyarrhythmia within a first electrical signal from a heart and determine, based on the tachyarrhythmia, to deliver anti-tachyarrhythmia shock therapy to the patient to treat the detected arrhythmia. The LPD may receive communication from the SICD requesting the LPD deliver anti-tachycardia pacing to the heart and determine, based on a second electrical signal from the heart sensed by the LPD, whether to deliver anti-tachycardia pacing (ATP) to the heart. In this manner, the SICD and LPD may communicate to coordinate ATP and/or cardioversion/defibrillation therapy. In another example, the LPD may be configured to deliver post-shock pacing after detecting delivery of anti-tachyarrhythmia shock therapy.

Abstract: Techniques and systems for monitoring cardiac arrhythmias and delivering electrical stimulation therapy using a subcutaneous implantable cardioverter defibrillator (SICD) and a leadless pacing device (LPD) are described. For example, the SICD may detect a tachyarrhythmia within a first electrical signal from a heart and determine, based on the tachyarrhythmia, to deliver anti-tachyarrhythmia shock therapy to the patient to treat the detected arrhythmia. The LPD may receive communication from the SICD requesting the LPD deliver anti-tachycardia pacing to the heart and determine, based on a second electrical signal from the heart sensed by the LPD, whether to deliver anti-tachycardia pacing (ATP) to the heart. In this manner, the SICD and LPD may communicate to coordinate ATP and/or cardioversion/defibrillation therapy. In another example, the LPD may be configured to deliver post-shock pacing after detecting delivery of anti-tachyarrhythmia shock therapy.

Abstract: A medical device performs a method for computing an estimate of a physiological variable. The method includes sensing a physiological signal and measuring an event of the physiological signal. The device initializes a value of a long-term metric of the event measurement, wherein the long-term metric corresponds to a time interval correlated to a response time of the physiological variable to changes in the event. The estimate of the long-term metric is updated in a memory of the medical device using a previous long-term metric and a current measurement of the event. The device detects a need for computing the physiological variable and computes an estimate of the physiological variable using the updated long-term metric.

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 of detecting cardiac signals in a medical device that includes decomposing a cardiac signal using a wavelet function at a plurality of scales to form a corresponding wavelet transform, determining approximation coefficients in response to the plurality of scales, reconstructing a first wavelet representation of the wavelet transform using predetermined approximation coefficients of the determined approximation coefficients, and evaluating the detected cardiac signals in response to the reconstructing.

Abstract: A medical device and associated method obtaining cardiac event intervals corresponding to a tachycardia interval. Evidence of a rhythm breaking point is obtained in response to sensing a cardiac event having a morphology corresponding to a supraventricular beat. A non-treatable rhythm is detected in response to the plurality of cardiac event intervals and the evidence of the rhythm breaking point.

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 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 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 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 obtaining cardiac event intervals corresponding to a tachycardia interval. Evidence of a rhythm breaking point is obtained in response to sensing a cardiac event having a morphology corresponding to a supraventricular beat. A non-treatable rhythm is detected in response to the plurality of cardiac event intervals and the evidence of the rhythm breaking point.

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 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.