Abstract: A medical device is configured to generate an acceleration signal and a temperature signal. The device is configured to determine an activity metric from the acceleration signal that is representative of patient physical activity. In response to determining that the activity metric is equal to or greater than a previously determined activity metric, the device is configured to adjust a target cardiac pacing rate based at least on a temperature change determined from the temperature signal. The device may include a pulse generator for generating cardiac pacing pulses based on the target cardiac pacing rate.

Abstract: A medical device is configured to sense a cardiac signal, determine a monitoring metric representative of activity of at least one heart chamber from the sensed cardiac signal, and determine that the monitoring metric meets expected rhythm criteria. The medical device may enable a monitoring feature of the medical device that is based on processing and analysis of the cardiac signal in response to the monitoring metric meeting the expected rhythm criteria.

Abstract: A medical device and method conserve electrical power used in monitoring cardiac arrhythmias. The device includes a sensing circuit configured to sense a cardiac signal, a power source and a control circuit having a processor powered by the power source. The control circuit is configured to operate in a normal state by waking up the processor to analyze the cardiac electrical signal for determining a state of an arrhythmia. The control circuit switches from the normal state to a power saving state that includes waking up the processor at a lower rate than during the normal state.

Abstract: A medical device includes a motion sensor configured to sense a motion signal. The medical device includes a control circuit configured to determine at least one ventricular event metric from the motion signal sensed over multiple of atrial cycles, determine that the ventricular event metric meets atrioventricular block criteria and generate an output in response to determining the atrioventricular block.

Abstract: A medical device and method conserve electrical power used in monitoring cardiac arrhythmias. The device includes a sensing circuit configured to sense a cardiac signal, a power source and a control circuit having a processor powered by the power source. The control circuit is configured to operate in a normal state by waking up the processor to analyze the cardiac electrical signal for determining a state of an arrhythmia. The control circuit switches from the normal state to a power saving state that includes waking up the processor at a lower rate than during the normal state.

Abstract: An implantable cardioverter defibrillator (ICD) receives a cardiac electrical signal by a sensing circuit while operating in a sensing without pacing mode and detects asystole based on the cardiac electrical signal. The ICD determines, in response to detecting the asystole, if asystole backup pacing is enabled, and automatically switches to a temporary pacing mode in response to the asystole backup pacing being enabled. Other examples of detecting asystole and providing a response to detecting asystole by the ICD are described herein.

Abstract: A medical system is configured to deliver an implantable medical device to a targeted implant site. The system may include a processor configured to receive a cardiac electrical signal and determine a feature of the cardiac electrical signal. The processor may be configured to determine a position of the delivery tool based on at least one feature of the cardiac electrical signal. The processor may detect a deployment position of the delivery tool in response to the cardiac electrical signal feature meeting criteria for detecting the deployment position.

Abstract: An implantable cardioverter defibrillator (ICD) receives a cardiac electrical signal by a sensing circuit while operating in a sensing without pacing mode and detects asystole based on the cardiac electrical signal. The ICD determines, in response to detecting the asystole, if asystole backup pacing is enabled, and automatically switches to a temporary pacing mode in response to the asystole backup pacing being enabled. Other examples of detecting asystole and providing a response to detecting asystole by the ICD are described herein.

Abstract: An implantable medical device system is configured to sense cardiac events in response to a cardiac electrical signal crossing a cardiac event sensing threshold. A control circuit is configured to determine a drop time interval based on a heart rate and control a sensing circuit to hold the cardiac event sensing threshold at a threshold value during the drop time interval.

Abstract: An implantable medical device system is configured to sense cardiac events in response to a cardiac electrical signal crossing a cardiac event sensing threshold. A control circuit is configured to determine a drop time interval based on a heart rate and control a sensing circuit to hold the cardiac event sensing threshold at a threshold value during the drop time interval.

Abstract: An implantable medical device system is configured to detect a tachyarrhythmia from a cardiac electrical signal and start an ATP therapy delay period. The implantable medical device determines whether the cardiac electrical signal received during the ATP therapy delay period satisfies ATP delivery criteria. A therapy delivery module is controlled to cancel the delayed ATP therapy if the ATP delivery criteria are not met and deliver the delayed ATP therapy if the ATP delivery criteria are met.

Abstract: A medical device and method conserve electrical power used in monitoring cardiac arrhythmias. The device includes a sensing circuit configured to sense a cardiac signal, a power source and a control circuit having a processor powered by the power source. The control circuit is configured to operate in a normal state by waking up the processor to analyze the cardiac electrical signal for determining a state of an arrhythmia. The control circuit switches from the normal state to a power saving state that includes waking up the processor at a lower rate than during the normal state.

Abstract: An implantable medical device system is configured to detect a tachyarrhythmia from a cardiac electrical signal and start an ATP therapy delay period. The implantable medical device determines whether the cardiac electrical signal received during the ATP therapy delay period satisfies ATP delivery criteria. A therapy delivery module is controlled to cancel the delayed ATP therapy if the ATP delivery criteria are not met and deliver the delayed ATP therapy if the ATP delivery criteria are met.

Abstract: An implantable medical device system and method for delivering cardiac resynchronization therapy (CRT) pacing that includes determining capture associated with the delivered CRT pacing is ineffective in response to the delivered CRT pacing. A reason for capture being ineffective is determined and a safety margin is adjusted if the determined reason for capture being ineffective is loss of capture and a left ventricle (LV) pre-excitation is adjusted if the determined reason for capture being ineffective is delayed LV depolarization. Monitoring for a change in effective cardiac resynchronization therapy is used to confirm that the adjustment of the CRT pacing was effective in resolving the ineffective capture.

Abstract: An implantable medical device system is configured to sense cardiac events in response to a cardiac electrical signal crossing a cardiac event sensing threshold. A control circuit is configured to determine a drop time interval based on a heart rate and control a sensing circuit to hold the cardiac event sensing threshold at a threshold value during the drop time interval.

Abstract: An implantable cardioverter defibrillator (ICD) receives a cardiac electrical signal by a sensing circuit while operating in a sensing without pacing mode and detects asystole based on the cardiac electrical signal. The ICD determines, in response to detecting the asystole, if asystole backup pacing is enabled, and automatically switches to a temporary pacing mode in response to the asystole backup pacing being enabled. Other examples of detecting asystole and providing a response to detecting asystole by the ICD are described herein.

Abstract: An implantable medical device system is configured to detect a tachyarrhythmia from a cardiac electrical signal and start an ATP therapy delay period. The implantable medical device determines whether the cardiac electrical signal received during the ATP therapy delay period satisfies ATP delivery criteria. A therapy delivery module is controlled to cancel the delayed ATP therapy if the ATP delivery criteria are not met and deliver the delayed ATP therapy if the ATP delivery criteria are met.

Abstract: An implantable cardioverter defibrillator (ICD) receives a cardiac electrical signal by a sensing circuit while operating in a sensing without pacing mode and detects asystole based on the cardiac electrical signal. The ICD determines, in response to detecting the asystole, if asystole backup pacing is enabled, and automatically switches to a temporary pacing mode in response to the asystole backup pacing being enabled. Other examples of detecting asystole and providing a response to detecting asystole by the ICD are described herein.

Abstract: An extra-cardiovascular implantable cardioverter defibrillator (ICD) having a high voltage therapy module is configured to control a high voltage charging circuit to charge a capacitor to a pacing voltage amplitude to deliver charge balanced pacing pulses. The capacitor is chargeable to a shock voltage amplitude that is greater than the pacing voltage amplitude. The ICD is configured to enable switching circuitry of the high voltage therapy module to discharge the capacitor to deliver a first pulse having a first polarity and a leading voltage amplitude corresponding to the pacing voltage amplitude for pacing the patient's heart via a pacing electrode vector selected from extra-cardiovascular electrodes. The high voltage therapy module delivers a second pulse after the first pulse. The second pulse has a second polarity opposite the first polarity and balances the electrical charge delivered during the first pulse.

Abstract: An implantable cardioverter defibrillator (ICD) receives a cardiac electrical signal by a sensing circuit while operating in a sensing without pacing mode and detects asystole based on the cardiac electrical signal. The ICD determines, in response to detecting the asystole, if asystole backup pacing is enabled, and automatically switches to a temporary pacing mode in response to the asystole backup pacing being enabled. Other examples of detecting asystole and providing a response to detecting asystole by the ICD are described herein.