Abstract: Rate responsive pacing is limited in an atrial based pacing mode by the AV interval in order to avoid or minimize ventricular encroachment of atrial pacing. The AV or VA interval is used to permit rate responsiveness; modulate rate responsiveness or to determine a dynamic upper sensor rate.

Abstract: An implantable medical device includes cardiac pacing functions. In order to reduce ventricular pacing, various modes are employed that tolerate missed ventricular beats, provide backup pacing and maintain overall AV synchrony. Upon the occurrence of a PVC, A-A timing is modified so that resultant V-V intervals are appropriate and ventricular pacing is avoided.

Abstract: An implantable medical device and associated method provide atrial pacing and measure an atrial ventricular (AV) delay. An autonomic function index is computed using the AV delay. The autonomic function index may be compiled in a medical report. In some embodiments, the autonomic function index is used to adjust atrial pacing control parameters.

Abstract: A pacing protocol is provided that reduces or minimizes ventricular pacing in favor of intrinsic conduction. When operating in a mode that provides ventricular pacing, a series of conduction checks are performed to determine if intrinsic conduction has returned. These conduction checks occur according to a predetermined pattern that general includes longer intervals between subsequent attempts. A maximum interval is provided such that conduction checks are not repeated sequentially at the same time of day when at this maximum interval.

Abstract: An atrial based pacing protocol promotes intrinsic conduction. An entire cardiac cycle is monitored for ventricular activity and permitted to lapse with ventricular activity. Ventricular pacing is available in a cardiac cycle immediately subsequent to such a skipped beat. When monitoring for intrinsic ventricular events, an event is expected within a given window. If no such event is detected, the cardiac cycle is truncated, leading to a shorter cycle that is devoid of ventricular activity. The subsequent cycle has a high likelihood of a ventricular sensed event and a greater than normal AV interval is provided prior to pacing.

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 adjustments to the delivered therapy, the adjustments being linearly dependent on characteristics of 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 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: An atrial based pacing protocol promotes intrinsic conduction. An entire cardiac cycle is monitored for ventricular activity and permitted to lapse with ventricular activity. Ventricular pacing is available in a cardiac cycle immediately subsequent to such a skipped beat. When monitoring for intrinsic ventricular events, an event is expected within a given window. If no such event is detected, the cardiac cycle in truncated, leading to a shorter cycle that is devoid of ventricular activity. The subsequent cycle has a high likelihood of a ventricular sensed event and a greater than normal AV interval is provided prior to pacing.

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 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.

Abstract: A pacing protocol is provided that reduces or minimizes ventricular pacing in favor of intrinsic conduction. When operating in a mode that provides ventricular pacing, a series of conduction checks are performed to determine if intrinsic conduction has returned. These conduction checks occur according to a predetermined pattern that generally includes longer intervals between subsequent attempts. The AV interval provided for dual chamber based pacing is modulated and generally moves from a larger value to a nominal value as the interval between unsuccessful conduction checks increases.

Abstract: Pacing parameters are provided to address cross talk and intrinsic ventricular events occurring within a predefined blanking period following an atrial event. The parameters are used in conjunction with protocol for minimizing or reducing ventricular pacing, wherein ignoring intrinsic ventricular events during the blanking period might otherwise affect the performance of the protocol.

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 apparatus sense a cardiac electrical signal and determine a signal quality parameter of the cardiac electrical signal. A number of shock pulses to be delivered to a patient's heart is determined in response to the signal quality parameter. Each of the shock pulses are scheduled to be delivered at a unique offset from a T-wave shock interval in one embodiment of the invention.

Abstract: Methods for determination of timing for electrical shocks to the heart to determine shock strength necessary to defibrillate a fibrillating heart. The timing corresponds the window of most vulnerability in the heart, which occurs during the T-wave of a heartbeat. Using a derivatized T-wave representation, the timing of most vulnerability is determined by a center of the area method, peak amplitude method, width method, or other similar methods. Devices are similarly disclosed embodying the methods of the present disclosure.

Abstract: Pacing parameters are provided to address cross talk and intrinsic ventricular events occurring within a predefined blanking period following an atrial event. The parameters are used in conjunction with protocol for minimizing or reducing ventricular pacing, wherein ignoring intrinsic ventricular events during the blanking period might otherwise affect the performance of the protocol.

Abstract: A preferred atrial-based pacing method and apparatus is provided using an intelligent cardiac pacing system to having the ability to continue atrial-based pacing as long as relatively reliable AV conduction is present. In the event that such relatively reliable AV conduction is not present, mode switching to a DDD/R or a DDI/R pacing mode while continually biased to mode switch back to atrial-based pacing. The standard or relatively reliable AV conduction may be changed either automatically or manually. This increases pacing that utilizes natural AV conduction however possible so as to gain all the benefits of cardiac contractile properties resulting therefrom, while tolerating the occasional missed ventricular depolarization (i.e., non-conducted P-wave). In the event where relatively reliable AV conduction is not present, the pacing mode is switched to a DDD/R mode while detecting a return of the relatively reliable AV conduction (and resulting mode switch to preferred atrial based pacing).

Abstract: An atrial based pacing protocol promotes intrinsic conduction. An entire cardiac cycle is monitored for ventricular activity and permitted to lapse with ventricular activity. Ventricular pacing is available in a cardiac cycle immediately subsequent to such a skipped beat. When monitoring for intrinsic ventricular events, an event is expected within a given window. If no such event is detected, the cardiac cycle in truncated, leading to a shorter cycle that is devoid of ventricular activity. The subsequent cycle has a high likelihood of a ventricular sensed event and a greater than normal AV interval is provided prior to pacing.