Abstract: An implantable device for terminating ventricular tachycardia is disclosed. The device includes a processor configured to determine a first antitachycardia pulse routine of N pulses. In the routine the first N?1 pulses are separated by a first cycle length and the Nth pulse is separated by a second cycle length that is shorter than the first cycle length. The device also comprises a lead coupled to the processor. The lead comprises an electrode configured to sense a tachycardia and further configured, under control of the processor, to administer the antitachycardia pulse routine.

Abstract: A method and apparatus for detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes, the plurality of electrodes forming a first sensing vector and a second sensing vector different from the first sensing vector, determining a characteristic associated with cardiac signals sensed along the first sensing vector during a predetermined sensing window, determining the characteristic associated with cardiac signals sensed along the second sensing vector during the predetermined sensing window, comparing the determined characteristic associated with cardiac signals sensed along the first sensing vector and the determined characteristic associated with cardiac signals sensed along the second sensing vector, and delivering a therapy in response to the comparing.

Abstract: A pressure sensor is deployed in the right atrium and is in contact with the tissue of the fossa ovalis. The fossa ovalis acts as a membrane and the pressure sensor determines the relative and/or absolute pressure within the left atrium while remaining within the right atrium. A variety of embodiment are provided to deploy and anchor the sensor into the proper position.

Abstract: An implantable medical device system and method in which the implantable device is adapted to operate in a minimum ventricular pacing mode. The device delivers cardiac pacing pulses in a first pacing mode during a normal mode of operation and upon detecting myocardial ischemia alters the first pacing mode in response to the myocardial ischemia detection.

Abstract: An implantable medical device system and method detect oversensing of cardiac signals. A cardiac signal including first events and second events is acquired. Cardiac events are sensed in response to the cardiac signal crossing a first threshold. A filtered cardiac signal is determined from the sensed cardiac signal, and a second threshold is determined from the filtered cardiac signal. A sensed cardiac event is classified either as a first event when the sensed cardiac event corresponds to a filtered cardiac signal peak crossing the second threshold or a second event when the sensed cardiac event corresponds to a filtered cardiac signal peak being less than the second threshold. Classification of sensed cardiac events as second events is used in determining oversensing.

Abstract: Method and apparatus for monitoring a plurality of physiological factors contributing to physiological conditions of a heart, that determines a first impedance, corresponding to the plurality of physiological factors, across a plurality of vectors, and a second impedance, corresponding to the plurality of physiological factors, across the plurality of vectors subsequent to determining the first impedance.

Abstract: An implantable medical device and associated method for automatically generating morphology templates during fast cardiac rhythms, confirming a provisional template as a confirmed template, and using the confirmed template to classify subsequent detected arrhythmias. A provisional SVT template may be created during a fast ventricular rate and activated as a confirmed SVT template upon verification that the fast rate was due to an SVT. The confirmed SVT template may be used to discriminate SVT from VT/VF.

Abstract: The invention is directed to techniques for monitoring organ rejection. An implanted device monitors the impedance of the transplanted organ. When the impedance measurements indicate that the organ is being rejected, the device provides early warning of rejection.

Abstract: A system and method for characterizing the atrial wall of the heart is provided. The characterization of the atrial wall can be used for a variety of diagnostic and therapeutic purposes. For example, it can be used to detect precursors to various types of hear disease, such as atrial fibrillation. In one embodiment, the system and method is used to determine a likelihood of fibrosis in the atrial wall. Furthermore, the system and method can detect changes in atrial wall fibrosis that can indicate a continuing degradation in the atrial wall health and an increasing likelihood of atrial fibrillation. In another embodiment, the system and method is used to determine if electrical instability exists in the atrial wall.

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 medical device identifies a hemodynamically unstable arrhythmia based upon optical hemodynamic sensor signals. The optical hemodynamic sensor includes a light source for transmitting light corresponding to first and second wavelengths through a blood perfused tissue of a patient and a light detector for generating optical signals corresponding to an intensity of the detected light at the first and second wavelengths. At a low motion period for the patient, optical signals are obtained from the optical hemodynamic sensor and are analyzed to determine a baseline motion level for the patient. Subsequent signals obtained from the optical hemodynamic sensor are compared to the baseline motion levels, with only those signals corresponding to periods where motion does not exceed the baseline level of motion being further analyzed to determine if they are consistent with a hemodynamically unstable arrhythmia.

Abstract: A pressure sensor is deployed in the right atrium and is in contact with the tissue of the fossa ovalis. The fossa ovalis acts as a membrane and the pressure sensor determines the relative and/or absolute pressure within the left atrium while remaining within the right atrium. A variety of embodiment are provided to deploy and anchor the sensor into the proper position.

Abstract: A method and apparatus for determining oversensing of cardiac signals that includes a housing containing electronic circuitry, an electrode coupled to the electronic circuitry to sense cardiac signals, and a processor, positioned within the housing, to determine an oversensing characteristic associated with the cardiac signals sensed over a predetermined sensing window, and to identify oversensing in response to the determined oversensing characteristic.

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 method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, determining whether the first sensing vector and the second sensing vector is corrupted by noise, and determining, in response to one of the first sensing vector and the second sensing vector being corrupted by noise, whether the other of the first sensing vector and the second sensing vector is one of a first cardiac event and a second cardiac event different from the first cardiac event.

Abstract: A method of detecting a cardiac event in a medical device that includes determining a first characteristic in response to cardiac signals sensed along a first sensing vector over a predetermined sensing window and in response to cardiac signals sensed along a second sensing vector over the predetermined sensing window, determining a second characteristic in response to cardiac signals sensed along the first sensing vector over the predetermined sensing window and in response to cardiac signals sensed along the second sensing vector over the predetermined sensing window, and determining a third characteristic in response to cardiac signals sensed along the first sensing vector over the predetermined sensing window and in response to cardiac signals sensed along the second sensing vector over the predetermined sensing window.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, determining inflections of the sensed cardiac signals, generating a pulse amplitude threshold in response to the determined inflections, and determining whether the inflections are indicative of noise in response to the determined inflections and the generated pulse amplitude threshold.

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: 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.