Abstract: Techniques for managing stored information in an implantable medical device system using multiple user accounts are described. An implantable medical device system may provide a general user account and a set of authenticable user accounts. In some examples, the general user account does not require a user of a programmer in an implantable medical device system to enter user identity information to manage information stored in the implantable medical device system. The general user account may be permitted to perform a subset of actions available to an authenticable user account. In some examples, an authenticable user account may rollback changes made to the stored information by the general user account. An authenticable user account may also be able to synchronize changes made to the stored information across all or some of the user accounts.

Abstract: In accordance with the techniques for heart monitoring described in this disclosure, an implantable medical device (IMD) may assess cardiac wall motion using impedance measurements through cardiac leads. As an example, the IMD may calculate an amount or rate of change in impedance due to the motion of a wall of the heart during at least a portion of one cardiac cycle, e.g., systole, in order to assess the strength of systolic contraction.

Abstract: In some examples, this disclosure describes techniques for assessing hemodynamic intolerance of ventricular pacing. A method comprises sensing a parameter indicative of autonomic tone during a first period in which a medical device delivers ventricular pacing to a patient, sensing the parameter indicative of autonomic tone during a second period in which the medical device does not deliver ventricular pacing to the patient, and assessing a level of change in autonomic tone in the patient induced by ventricular pacing based on values of the sensed parameter during the first and second periods.

Abstract: In some examples, this disclosure describes techniques for assessing hemodynamic intolerance of ventricular pacing. A method comprises sensing a parameter indicative of autonomic tone during a first period in which a medical device delivers ventricular pacing to a patient, sensing the parameter indicative of autonomic tone during a second period in which the medical device does not deliver ventricular pacing to the patient, and assessing a level of change in autonomic tone in the patient induced by ventricular pacing based on values of the sensed parameter during the first and second periods.

Abstract: Techniques for managing stored information in an implantable medical device system using multiple user accounts are described. An implantable medical device system may provide a general user account and a set of authenticable user accounts. In some examples, the general user account does not require a user of a programmer in an implantable medical device system to enter user identity information to manage information stored in the implantable medical device system. The general user account may be permitted to perform a subset of actions available to an authenticable user account. In some examples, an authenticable user account may rollback changes made to the stored information by the general user account. An authenticable user account may also be able to synchronize changes made to the stored information across all or some of the user accounts.

Abstract: In some examples, this disclosure describes techniques for assessing hemodynamic intolerance of ventricular pacing. A method comprises sensing a parameter indicative of autonomic tone during a first period in which a medical device delivers ventricular pacing to a patient, sensing the parameter indicative of autonomic tone during a second period in which the medical device does not deliver ventricular pacing to the patient, and assessing a level of change in autonomic tone in the patient induced by ventricular pacing based on values of the sensed parameter during the first and second periods.

Abstract: Techniques for managing stored information in an implantable medical device system using multiple user accounts are described. An implantable medical device system may provide a general user account and a set of authenticable user accounts. In some examples, the general user account does not require a user of a programmer in an implantable medical device system to enter user identity information to manage information stored in the implantable medical device system. The general user account may be permitted to perform a subset of actions available to an authenticable user account. In some examples, an authenticable user account may rollback changes made to the stored information by the general user account. An authenticable user account may also be able to synchronize changes made to the stored information across all or some of the user accounts.

Abstract: This disclosure describes various techniques for discriminating supraventricular tachycardia (SVT) from ventricular tachycardia (VT). As one example, a method includes detecting a tachycardia rhythm, identifying a rate of change in heart rate corresponding to the tachycardia rhythm, identifying a rate of change in heart rate variability corresponding to the tachycardia rhythm, and classifying the tachycardia rhythm as at least one of supraventricular tachycardia or ventricular tachycardia based on the rate of change in heart rate and rate of change in heart rate variability.

Abstract: An example implantable medical device (IMD), such as an implantable cardioverter defibrillator, may be configured to store a ventricular tachycardia zone, wherein the ventricular tachycardia zone specifies ventricular depolarization rates indicative of ventricular tachycardia, and to deliver pacing pulses to at least one ventricle of a heart in response to detecting intrinsic atrial depolarizations at rates within the ventricular tachycardia zone. The IMD may further store a maximum ventricular tracking rate that is greater than a lower bound of the ventricular tachycardia zone, and be further configured to deliver the pacing pulses to the at least one ventricle in response to detecting intrinsic atrial depolarizations at rates up to the maximum ventricular rate. In this manner, the IMD may be configured with overlapping pacing and tachyarrhythmia detection zones.

Abstract: Systems and methods are provided for monitoring a cardiac condition of a patient. The system includes a sensor for receiving a patient's heart rate and a processor that is programmable to set a patient's safe heart rate zone. The processor is also configured to determine whether the patient's heart rate has exceeded the safe heart rate zone. In response to determining that the patient's heart rate has exceeded the safe heart rate zone, the processor may reprogram a new safe heart rate zone.

Abstract: In general, this disclosure provides techniques for heart monitoring. In accordance with the techniques described in this disclosure, an implantable medical device (IMD) may assess cardiac wall motion using impedance measurements through cardiac leads. As an example, the IMD may calculate an amount or rate of change in impedance due to the motion of a wall of the heart during at least a portion of one cardiac cycle, e.g., systole, in order to assess the strength of systolic contraction.

Abstract: An example implantable medical device (IMD), such as an implantable cardioverter defibrillator, may be configured to store a ventricular tachycardia zone, wherein the ventricular tachycardia zone specifies ventricular depolarization rates indicative of ventricular tachycardia, and to deliver pacing pulses to at least one ventricle of a heart in response to detecting intrinsic atrial depolarizations at rates within the ventricular tachycardia zone. The IMD may further store a maximum ventricular tracking rate that is greater than a lower bound of the ventricular tachycardia zone, and be further configured to deliver the pacing pulses to the at least one ventricle in response to detecting intrinsic atrial depolarizations at rates up to the maximum ventricular rate. In this manner, the IMD may be configured with overlapping pacing and tachyarrhythmia detection zones.

Abstract: Techniques for managing stored information in an implantable medical device system using multiple user accounts are described. An implantable medical device system may provide a general user account and a set of authenticable user accounts. In some examples, the general user account does not require a user of a programmer in an implantable medical device system to enter user identity information to manage information stored in the implantable medical device system. The general user account may be permitted to perform a subset of actions available to an authenticable user account. In some examples, an authenticable user account may rollback changes made to the stored information by the general user account. An authenticable user account may also be able to synchronize changes made to the stored information across all or some of the user accounts.

Abstract: In some examples, this disclosure describes techniques for assessing hemodynamic intolerance of ventricular pacing. A method comprises sensing a parameter indicative of autonomic tone during a first period in which a medical device delivers ventricular pacing to a patient, sensing the parameter indicative of autonomic tone during a second period in which the medical device does not deliver ventricular pacing to the patient, and assessing a level of change in autonomic tone in the patient induced by ventricular pacing based on values of the sensed parameter during the first and second periods.

Abstract: This disclosure describes various techniques for discriminating supraventricular tachycardia (SVT) from ventricular tachycardia (VT). As one example, a method includes detecting a tachycardia rhythm, identifying a rate of change in heart rate corresponding to the tachycardia rhythm, identifying a rate of change in heart rate variability corresponding to the tachycardia rhythm, and classifying the tachycardia rhythm as at least one of supraventricular tachycardia or ventricular tachycardia based on the rate of change in heart rate and rate of change in heart rate variability.

Abstract: Systems and methods are provided for monitoring a cardiac condition of a patient. The system includes a sensor for receiving a patient's heart rate and a processor that is programmable to set a patient's safe heart rate zone. The processor is also configured to determine whether the patient's heart rate has exceeded the safe heart rate zone. In response to determining that the patient's heart rate has exceeded the safe heart rate zone, the processor may reprogram a new safe heart rate zone.