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 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 capable of sensing cardiac electrical signals includes a sensing circuit, a therapy delivery circuit and a control circuit. The sensing circuit is configured to receive a cardiac electrical signal and sense a cardiac event in response to the signal crossing a cardiac event sensing threshold. The therapy delivery circuit is configured to deliver an electrical stimulation therapy to a patient's heart via the electrodes coupled to the implantable medical device. The control circuit is configured to control the sensing circuit to set a starting value of the cardiac event sensing threshold and hold the starting value constant for a sense delay interval. The control circuit is further configured to detect an arrhythmia based on cardiac events sensed by the sensing circuit and control the therapy delivery circuit to deliver the electrical stimulation therapy in response to detecting the arrhythmia.

Abstract: An implantable medical device system capable of sensing cardiac electrical signals includes a sensing circuit, a therapy delivery circuit and a control circuit. The sensing circuit is configured to receive a cardiac electrical signal and sense a cardiac event in response to the signal crossing a cardiac event sensing threshold. The therapy delivery circuit is configured to deliver an electrical stimulation therapy to a patient's heart via the electrodes coupled to the implantable medical device. The control circuit is configured to control the sensing circuit to set a starting value of the cardiac event sensing threshold and hold the starting value constant for a sense delay interval. The control circuit is further configured to detect an arrhythmia based on cardiac events sensed by the sensing circuit and control the therapy delivery circuit to deliver the electrical stimulation therapy in response to detecting the arrhythmia.

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 capable of sensing cardiac electrical signals includes a sensing circuit, a therapy delivery circuit and a control circuit. The sensing circuit is configured to receive a cardiac electrical signal and sense a cardiac event in response to the signal crossing a cardiac event sensing threshold. The therapy delivery circuit is configured to deliver an electrical stimulation therapy to a patient's heart via the electrodes coupled to the implantable medical device. The control circuit is configured to control the sensing circuit to set a starting value of the cardiac event sensing threshold and hold the starting value constant for a sense delay interval. The control circuit is further configured to detect an arrhythmia based on cardiac events sensed by the sensing circuit and control the therapy delivery circuit to deliver the electrical stimulation therapy in response to detecting the arrhythmia.

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 capable of sensing cardiac electrical signals includes a sensing circuit, a therapy delivery circuit and a control circuit. The sensing circuit is configured to receive a cardiac electrical signal and sense a cardiac event in response to the signal crossing a cardiac event sensing threshold. The therapy delivery circuit is configured to deliver an electrical stimulation therapy to a patient's heart via the electrodes coupled to the implantable medical device. The control circuit is configured to control the sensing circuit to set a starting value of the cardiac event sensing threshold and hold the starting value constant for a sense delay interval. The control circuit is further configured to detect an arrhythmia based on cardiac events sensed by the sensing circuit and control the therapy delivery circuit to deliver the electrical stimulation therapy in response to detecting the arrhythmia.

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 medical device system capable of sensing cardiac electrical signals includes a sensing circuit, a therapy delivery circuit and a control circuit. The sensing circuit is configured to receive a cardiac electrical signal and sense a cardiac event in response to the signal crossing a cardiac event sensing threshold. The therapy delivery circuit is configured to deliver an electrical stimulation therapy to a patient's heart via the electrodes coupled to the implantable medical device. The control circuit is configured to control the sensing circuit to set a starting value of the cardiac event sensing threshold and hold the starting value constant for a sense delay interval. The control circuit is further configured to detect an arrhythmia based on cardiac events sensed by the sensing circuit and control the therapy delivery circuit to deliver the electrical stimulation therapy in response to detecting the arrhythmia.