摘要:
This document discusses, among other things, systems, devices, and methods measure an impedance and, in response, adjust an atrioventricular (AV) delay or other cardiac resynchronization therapy (CRT) parameter that synchronizes left and right ventricular contractions. A first example uses parameterizes a first ventricular volume against a second ventricular volume during a cardiac cycle, using a loop area to create a synchronization fraction (SF). The CRT parameter is adjusted in closed-loop fashion to increase the SF. A second example measures a septal-freewall phase difference (PD), and adjusts a CRT parameter to decrease the PD. A third example measures a peak-to-peak volume or maximum rate of change in ventricular volume, and adjusts a CRT parameter to increase the peak-to-peak volume or maximum rate of change in the ventricular volume.
摘要:
This document discusses, among other things, a cardiac function management device or other implantable medical device that includes a test mode and a diagnostic mode. During a test mode, the device cycles through various electrode configurations for collecting thoracic impedance data. At least one figure of merit is calculated from the impedance data for each such electrode configuration. In one example, only non-arrhythmic beats are used for computing the figure of merit. A particular electrode configuration is automatically selected using the figure of merit. During a diagnostic mode, the device collects impedance data using the selected electrode configuration. In one example, the figure of merit includes a ratio of a cardiac stroke amplitude and a respiration amplitude. Other examples of the figure of merit are also described.
摘要:
Biventricular-triggered pacing is a pacing mode that can employ in cardiac resynchronization pacing at elevated heart rates. Described herein are methods and devices for implementing biventricular pacing in the context of multi-site left ventricular pacing.
摘要:
This document discusses, among other things, systems, devices, and methods measure an impedance and, in response, adjust an atrioventricular (AV) delay or other cardiac resynchronization therapy (CRT) parameter that synchronizes left and right ventricular contractions. A first example uses parameterizes a first ventricular volume against a second ventricular volume during a cardiac cycle, using a loop area to create a synchronization fraction (SF). The CRT parameter is adjusted in closed-loop fashion to increase the SF. A second example measures a septal-freewall phase difference (PD), and adjusts a CRT parameter to decrease the PD. A third example measures a peak-to-peak volume or maximum rate of change in ventricular volume, and adjusts a CRT parameter to increase the peak-to-peak volume or maximum rate of change in the ventricular volume.
摘要:
Biventricular-triggered pacing is a pacing mode that can employ in cardiac resynchronization pacing at elevated heart rates. Described herein are methods and devices for implementing biventricular pacing in the context of multi-site left ventricular pacing.
摘要:
Vector selection is automatically achieved via a thoracic or intracardiac impedance signal collected in a cardiac function management device or other implantable medical device that includes a test mode and a diagnostic mode. During a test mode, the device cycles through various electrode configurations for collecting thoracic impedance data. At least one figure of merit is calculated from the impedance data for each such electrode configuration. In one example, only non-arrhythmic beats are used for computing the figure of merit. A particular electrode configuration is automatically selected using the figure of merit. During a diagnostic mode, the device collects impedance data using the selected electrode configuration. In one example, the figure of merit includes a ratio of a cardiac stroke amplitude and a respiration amplitude. Other examples of the figure of merit are also described.
摘要:
Vector selection is automatically achieved via a thoracic or intracardiac impedance signal collected in a cardiac function management device or other implantable medical device that includes a test mode and a diagnostic mode. During a test mode, the device cycles through various electrode configurations for collecting thoracic impedance data. At least one figure of merit is calculated from the impedance data for each such electrode configuration. In one example, only non-arrhythmic beats are used for computing the figure of merit. A particular electrode configuration is automatically selected using the figure of merit. During a diagnostic mode, the device collects impedance data using the selected electrode configuration. In one example, the figure of merit includes a ratio of a cardiac stroke amplitude and a respiration amplitude. Other examples of the figure of merit are also described.
摘要:
An apparatus comprises an implantable cardiac signal sensing circuit that provides an electrical cardiac signal representative of cardiac activity of a subject, an implantable therapy circuit that delivers electrical pacing stimulation energy to a heart of a subject, and a controller circuit. The controller circuit includes a chronotropic incompetence detection circuit that initiates pacing of an atrium of the subject at a rate higher than a device-indicated rate or a sensed intrinsic rate, monitor the AV interval, initiates an increase in the pacing rate while continuing the monitoring of the AV interval, calculates a change in AV intervals between a highest paced rate used in the monitoring and a lowest paced rate used in the monitoring, and indicates that the AV intervals are evidence of chronotropic incompetence when the calculated change in the AV intervals exceeds a specified threshold AV interval change value.