Abstract: In a possible implementation, a method for cardiac testing is provided which includes measuring test data associated with cardiac events and storing the test data in an intracardiac stimulation device. The method further includes acquiring event electrograms corresponding with the test data and storing the event electrograms corresponding with the test data in the intracardiac stimulation device. In a possible implementation, marker data is stored associating event electrograms with measured test data, which may identify the event electrograms used for measuring the test data and/or identify when adjacent event electrograms are not contiguous. In some implementations, the test data may be measured and stored in an out-of-clinic test, and the test data and the corresponding event electrograms may be later retrieved from the intracardiac stimulation device and presented on a visual display.

Abstract: In a possible implementation, a method for cardiac testing is provided which includes measuring test data associated with cardiac events and storing the test data in an intracardiac stimulation device. The method further includes acquiring event electrograms corresponding with the test data and storing the event electrograms corresponding with the test data in the intracardiac stimulation device. In a possible implementation, marker data is stored associating event electrograms with measured test data, which may identify the event electrograms used for measuring the test data and/or identify when adjacent event electrograms are not contiguous. In some implementations, the test data may be measured and stored in an out-of-clinic test, and the test data and the corresponding event electrograms may be later retrieved from the intracardiac stimulation device and presented on a visual display.

Abstract: Techniques are described for discriminating ventricular tachycardia (VT) from supraventricular tachycardia (SVT) in circumstances when the ventricular rate exceeds the atrial rate (i.e. V>A). In one example, an initial atrial rate is detected while employing adjustable atrial channel detection parameters that can affect the detection of the true atrial rate—such as a post-ventricular atrial blanking (PVAB) interval or an atrial channel sensitivity level. If the ventricular rate exceeds a VT rate zone threshold with V>A, the device does not immediately deliver high voltage shock therapy as done in other devices. Rather, the device instead selectively adjusts the atrial channel detection parameter(s) to determine if the true atrial rate is equal to the ventricular rate. If so, then such is an indication that the arrhythmia might be SVT rather than VT and various discrimination procedures are employed to distinguish SVT from VT before therapy is delivered.

Abstract: In a possible implementation, a method for cardiac testing is provided which includes measuring test data associated with cardiac events and storing the test data in an intracardiac stimulation device. The method further includes acquiring event electrograms corresponding with the test data and storing the event electrograms corresponding with the test data in the intracardiac stimulation device. In a possible implementation, marker data is stored associating event electrograms with measured test data, which may identify the event electrograms used for measuring the test data and/or identify when adjacent event electrograms are not contiguous. In some implementations, the test data may be measured and stored in an out-of-clinic test, and the test data and the corresponding event electrograms may be later retrieved from the intracardiac stimulation device and presented on a visual display.

Abstract: Techniques are described for discriminating ventricular tachycardia (VT) from supraventricular tachycardia (SVT) in circumstances when the ventricular rate exceeds the atrial rate (i.e. V>A). In one example, an initial atrial rate is detected while employing adjustable atrial channel detection parameters that can affect the detection of the true atrial rate—such as a post-ventricular atrial blanking (PVAB) interval or an atrial channel sensitivity level. If the ventricular rate exceeds a VT rate zone threshold with V>A, the device does not immediately deliver high voltage shock therapy as done in other devices. Rather, the device instead selectively adjusts the atrial channel detection parameter(s) to determine if the true atrial rate is equal to the ventricular rate. If so, then such is an indication that the arrhythmia might be SVT rather than VT and various discrimination procedures are employed to distinguish SVT from VT before therapy is delivered.

Abstract: An implantable cardiac stimulation device and associated method capable of delivering non-invasive programmed stimulation for electrophysiological testing in which the onset of the non-invasive programmed stimulation is triggered by a cardiac event, either a detected intrinsic event or a stimulated event, occurring in the heart chamber to be tested. When a non-invasive programmed stimulation command is received by the implanted device, it switches to a routine that allows transition to a non-invasive programmed stimulation from a standard operating mode, during a refractory period. The stimulation device also provides a recovery delay following the last pulse of a non-invasive programmed stimulation sequence. If no intrinsic activity is detected during the recovery delay, a refractory period is started following the expiration of the recovery delay.

Abstract: A pacemaker or other implantable cardiac stimulation device is configured with both a rate hysteresis mode and a vasovagal syncope prevention mode. Within the rate hysteresis mode, the pacemaker detects when the intrinsic heart rate of the patient is below an escape rate, then paces the heart at a Base Rate until an intrinsic beat is detected. When programmed in the vasovagal syncope prevention mode, upon detecting the intrinsic rate falling below the Hysteresis Escape Rate, the pacemaker paces the heart at a Vasovagal Syncope Response Rate, which is considerably higher than the Base Rate. The pacemaker is preferably set to the syncope prevention mode for patients prone to recurrent vasovagal syncope. By pacing the heart at the higher Vasovagal Syncope Response Rate, the pacemaker thereby helps prevent a significant drop in blood pressure which might otherwise cause a loss of consciousness in the patient. System and method embodiments are described.

Abstract: A pacemaker or other implantable cardiac stimulation device is configured with both a rate hysteresis mode and a vasovagal syncope prevention mode. Within the rate hysteresis mode, the pacemaker detects when the intrinsic heart rate of the patient is below an escape rate, then paces the heart at a Base Rate until an intrinsic beat is detected. When programmed in the vasovagal syncope prevention mode, upon detecting the intrinsic rate falling below the Hysteresis Escape Rate, the pacemaker paces the heart at a Vasovagal Syncope Response Rate, which is considerably higher than the Base Rate. The pacemaker is preferably set to the syncope prevention mode for patients prone to recurrent vasovagal syncope. By pacing the heart at the higher Vasovagal Syncope Response Rate, the pacemaker thereby helps prevent a significant drop in blood pressure which might otherwise cause a loss of consciousness in the patient. System and method embodiments are described.

Abstract: A pacemaker or other implantable cardiac stimulation device is configured with both a rate hysteresis mode and a vasovagal syncope prevention mode. Within the rate hysteresis mode, the pacemaker detects when the intrinsic heart rate of the patient is below an escape rate, then paces the heart at a Base Rate until an intrinsic beat is detected. When programmed in the vasovagal syncope prevention mode, upon detecting the intrinsic rate falling below the Hysteresis Escape Rate, the pacemaker paces the heart at a Vasovagal Syncope Response Rate, which is considerably higher than the Base Rate. The pacemaker is preferably set to the syncope prevention mode for patients prone to recurrent vasovagal syncope. By pacing the heart at the higher Vasovagal Syncope Response Rate, the pacemaker thereby helps prevent a significant drop in blood pressure which might otherwise cause a loss of consciousness in the patient. System and method embodiments are described.

Abstract: A pacemaker or other implantable cardiac stimulation device is configured with both a rate hysteresis mode and a vasovagal syncope prevention mode. Within the rate hysteresis mode, the pacemaker detects when the intrinsic heart rate of the patient is below an escape rate, then paces the heart at a Base Rate until an intrinsic beat is detected. When programmed in the vasovagal syncope prevention mode, upon detecting the intrinsic rate falling below the Hysteresis Escape Rate, the pacemaker paces the heart at a Vasovagal Syncope Response Rate, which is considerably higher than the Base Rate. The pacemaker is preferably set to the syncope prevention mode for patients prone to recurrent vasovagal syncope. By pacing the heart at the higher Vasovagal Syncope Response Rate, the pacemaker thereby helps prevent a significant drop in blood pressure which might otherwise cause a loss of consciousness in the patient. System and method embodiments are described.

Abstract: An implantable dual-chamber pacemaker programmed to operate primarily in an atrial tracking mode includes an atrial rate smoothing filter for producing a filtered atrial rate (FAR) from an intrinsic atrial rate. The pacemaker automatically switches its mode of operation from an atrial tracking mode (i.e., DDD, DDDR, VDD, VDDR, DDT or DDTR) to a non-atrial tracking mode (i.e., DDI, DDIR, VDI, VDIR, DDT or DDTR), in the event the filtered atrial rate exceeds a prescribed upper rate limit. Synchronously with this mode switch, the pacemaker automatically shortens a post ventricular atrial refractory period (PVARP) to a minimum, predefined or programmable value. In one embodiment, the shortened PVARP is set equal to a post ventricular atrial blanking period (PVAB) that ranges between approximately 50 msec and 200 msec. While in the alternate mode of operation, the pacemaker maintains the shortened PVARB refractory period, and continues to monitor the FAR.