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.

A cardiac pacing system having a pulse generator for generating therapeutic electric pulses, a lead electrically coupled with the pulse generator having an electrode, a first sensor configured to monitor a physiological characteristic of a patient, a second sensor configured to monitor a second physiological characteristic of a patient and a controller. The controller can determine a pacing vector based on variables including a signal received from the second sensor, and cause the pulse generator to deliver the therapeutic electrical pulses according to the determined pacing vector. The controller can also modify pacing characteristics based on variables including a signal received from the second sensor.

For use by an implantable system including a first and second leadless pacemakers (LPs) implanted, respectively, in first and second cardiac chambers, a method comprises storing, within memory of the first LP, a paced activation morphology template corresponding to far-field signal components expected to be present in an EGM sensed by the first LP when a pacing pulse delivered to the second cardiac chamber by the second LP captures the second cardiac chamber. The method also includes the first LP comparing a morphology of a portion of an EGM sensed by the first LP to the paced activation morphology template to determine whether a match therebetween is detected, and determining whether capture of the second cardiac chamber occurred or failed to occur, based on whether the first LP detects a match between the morphology of the portion of the EGM and the paced activation morphology template.

A ventricularly implantable medical device that includes a sensing module that is configured to detect an atrial fiducial and identify an atrial contraction based at least on part on the detected atrial fiducial. Control circuitry in the implantable medical device is configured to deliver a ventricular pacing therapy to a patient's heart based at least in part on the identified atrial contraction, and can automatically switch or revert the ventricular pacing therapies on the fly.

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.

A cardiac pacing system having a pulse generator for generating therapeutic electric pulses, a lead electrically coupled with the pulse generator having an electrode, a first sensor configured to monitor a physiological characteristic of a patient, a second sensor configured to monitor a second physiological characteristic of a patient and a controller. The controller can determine a pacing vector based on variables including a signal received from the second sensor, and cause the pulse generator to deliver the therapeutic electrical pulses according to the determined pacing vector. The controller can also modify pacing characteristics based on variables including a signal received from the second sensor.

A cardiac pacing system having a pulse generator for generating therapeutic electric pulses, a lead electrically coupled with the pulse generator having an electrode, a first sensor configured to monitor a physiological characteristic of a patient, a second sensor configured to monitor a second physiological characteristic of a patient and a controller. The controller can determine a pacing vector based on variables including a signal received from the second sensor, and cause the pulse generator to deliver the therapeutic electrical pulses according to the determined pacing vector. The controller can also modify pacing characteristics based on variables including a signal received from the second sensor.

A cardiac pacing system having a pulse generator for generating therapeutic electric pulses, a lead electrically coupled with the pulse generator having an electrode, a first sensor configured to monitor a physiological characteristic of a patient, a second sensor configured to monitor a second physiological characteristic of a patient and a controller. The controller can determine a pacing vector based on variables including a signal received from the second sensor, and cause the pulse generator to deliver the therapeutic electrical pulses according to the determined pacing vector. The controller can also modify pacing characteristics based on variables including a signal received from the second sensor.

A cardiac pacing system having a pulse generator for generating therapeutic electric pulses, a lead electrically coupled with the pulse generator having an electrode, a first sensor configured to monitor a physiological characteristic of a patient, a second sensor configured to monitor a second physiological characteristic of a patient and a controller. The controller can determine a pacing vector based on variables including a signal received from the second sensor, and cause the pulse generator to deliver the therapeutic electrical pulses according to the determined pacing vector. The controller can also modify pacing characteristics based on variables including a signal received from the second sensor.

A cardiac pacing system having a pulse generator for generating therapeutic electric pulses, a lead electrically coupled with the pulse generator having an electrode, a first sensor configured to monitor a physiological characteristic of a patient, a second sensor configured to monitor a second physiological characteristic of a patient and a controller. The controller can determine a pacing vector based on variables including a signal received from the second sensor, and cause the pulse generator to deliver the therapeutic electrical pulses according to the determined pacing vector. The controller can also modify pacing characteristics based on variables including a signal received from the second sensor.