Abstract: A medical device is configured to sense a cardiac signal that includes far field ventricular event signals and determine a ventricular activity metric from the sensed cardiac signal. The ventricular activity metric may be representative of a ventricular rate or an atrioventricular time interval. The medical device is configured to determine an atrioventricular synchrony metric based on the ventricular activity metric and generate an output based on the atrioventricular synchrony metric. The device may include a memory configured to store data corresponding to the atrioventricular synchrony metric.

Abstract: A medical device is configured to sense a cardiac signal that includes far field ventricular event signals and determine a ventricular activity metric from the sensed cardiac signal. The ventricular activity metric may be representative of a ventricular rate or an atrioventricular time interval. The medical device is configured to determine an atrioventricular synchrony metric based on the ventricular activity metric and generate an output based on the atrioventricular synchrony metric. The device may include a memory configured to store data corresponding to the atrioventricular synchrony metric.

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: 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 ventricular pacemaker is configured to determine a ventricular rate interval by determining at least one ventricular event interval between two consecutive ventricular events and determine a rate smoothing ventricular pacing interval based on the ventricular rate interval. The pacemaker is further configured to detect an atrial event from a sensor signal and deliver a ventricular pacing pulse in response to detecting the atrial event from the sensor signal. The pacemaker may start the rate smoothing ventricular pacing interval to schedule a next pacing pulse to be delivered upon expiration of the rate smoothing ventricular pacing interval.

Abstract: A ventricular pacemaker is configured to determine a ventricular rate interval by determining at least one ventricular event interval between two consecutive ventricular events and determine a rate smoothing ventricular pacing interval based on the ventricular rate interval. The pacemaker is further configured to detect an atrial event from a sensor signal and deliver a ventricular pacing pulse in response to detecting the atrial event from the sensor signal. The pacemaker may start the rate smoothing ventricular pacing interval to schedule a next pacing pulse to be delivered upon expiration of the rate smoothing ventricular pacing interval.

Abstract: A medical device is configured to sense a cardiac electrical signal and detect an atrial tachyarrhythmia based on the sensed cardiac electrical signal. The medical device is configured to determine that far field oversensing criteria are met by the cardiac electrical signal during the detected atrial tachyarrhythmia. The medical device may detect termination of the detected atrial tachyarrhythmia in response to the far field oversensing criteria being met.

Abstract: A pacemaker is configured to operate in an atrial synchronous ventricular pacing mode and, after expiration of a conduction check time interval, switch to an asynchronous ventricular pacing mode that includes setting a ventricular pacing interval to a base pacing rate interval. The pacemaker is further configured to determine when atrioventricular block detection criteria are satisfied during the asynchronous ventricular pacing mode and, responsive to the atrioventricular block detection criteria being satisfied, switch back to the atrial synchronous ventricular pacing mode.

Abstract: A medical device is configured to sense an acceleration signal and determine at least one frequency metric from the acceleration signal that is correlated to a frequency of oscillations of the acceleration signal. The medial device is configured to determine that the at least one frequency metric meets atrial tachyarrhythmia criteria and detect an atrial tachyarrhythmia in response to at least the frequency metric meeting the atrial tachyarrhythmia criteria.

Abstract: A medical device is configured to sense a cardiac signal that includes far field ventricular event signals and determine a ventricular activity metric from the sensed cardiac signal. The ventricular activity metric may be representative of a ventricular rate or an atrioventricular time interval. The medical device is configured to determine an atrioventricular synchrony metric based on the ventricular activity metric and generate an output based on the atrioventricular synchrony metric. The device may include a memory configured to store data corresponding to the atrioventricular synchrony metric.

Abstract: A medical device is configured to produce a cardiac motion signal by sampling a signal produced by an axis of a motion sensor, starting a blanking period, suspending the sampling of the signal during at least a portion of the blanking period, and restarting the sampling of the signal at the sampling frequency before the blanking period has expired. The medical device may detect a cardiac event from the cardiac motion signal and generate a pacing pulse in response to detecting the cardiac event in some examples.

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 pacemaker is configured to operate in an atrial synchronous ventricular pacing mode and, after expiration of a conduction check time interval, switch to an asynchronous ventricular pacing mode that includes setting a ventricular pacing interval to a base pacing rate interval. The pacemaker is further configured to determine when atrioventricular block detection criteria are satisfied during the asynchronous ventricular pacing mode and, responsive to the atrioventricular block detection criteria being satisfied, switch back to the atrial synchronous ventricular pacing mode.

Abstract: A medical device is configured to produce a cardiac motion signal by sampling a signal produced by an axis of a motion sensor, starting a blanking period, suspending the sampling of the signal during at least a portion of the blanking period, and restarting the sampling of the signal at the sampling frequency before the blanking period has expired. The medical device may detect a cardiac event from the cardiac motion signal and generate a pacing pulse in response to detecting the cardiac event in some examples.

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: A medical device comprises therapy delivery circuitry and processing circuitry. The therapy delivery circuitry is configured to deliver anti-tachycardia pacing (ATP) therapy to a heart of a patient. The ATP therapy includes one or more pulse trains and each of the one or more pulse trains includes a plurality of pacing pulses. The processing circuitry is configured to, for at least one of the plurality of pacing pulses of at least one of the one or more pulse trains, determine at least one latency metric of an evoked response of the heart to the pacing pulse. The processing circuitry is further configured to modify the ATP therapy based on the at least one latency metric.

Abstract: A medical device comprises therapy delivery circuitry and processing circuitry. The therapy delivery circuitry is configured to deliver anti-tachycardia pacing (ATP) therapy to a heart of a patient. The ATP therapy includes one or more pulse trains and each of the one or more pulse trains includes a plurality of pacing pulses. The processing circuitry is configured to, for at least one of the plurality of pacing pulses of at least one of the one or more pulse trains, determine at least one latency metric of an evoked response of the heart to the pacing pulse. The processing circuitry is further configured to modify the ATP therapy based on the at least one latency metric.