Pacing mode switching in a ventricular pacemaker

A medical device, comprising:

• a motion sensor configured to sense a motion signal;
• a pulse generator configured to deliver ventricular pacing pulses;
• and
• a control circuit configured to:
• determine a first patient physical activity metric from the motion signal;
• determine an actual ventricular rate based on a plurality of ventricular pacing pulses delivered by the pulse generator, each of the plurality of ventricular pacing pulses being delivered by the pulse generator in response to an atrioventricular pacing interval expiring;
• determine that first pacing mode switching criteria are met based on the first patient physical activity metric and the actual ventricular rate;
• and
• control the pulse generator to deliver ventricular pacing pulses according to a ventricular lower rate in response to the first pacing mode switching criteria being met, wherein the control circuit is further configured to:
• control the pulse generator to generate the ventricular pacing pulses according to the ventricular lower rate for a minimum mode switch time interval;
• determine that the minimum mode switch time interval is expired;
• determine a second patient activity metric from the motion signal;
• after the minimum mode switch time interval is expired, determine that second pacing mode switching criteria are met based on the second patient activity metric;
• and
• switch to an atrioventricular tracking pacing mode in response to the second pacing mode switching criteria being met.

A method, comprising:

• sensing a motion signal;
• determining a first patient physical activity metric from the motion signal;
• determining an actual ventricular rate based on a plurality of ventricular pacing pulses, each of the plurality of ventricular pacing pulses being delivered in response to an atrioventricular pacing interval expiring;
• determining that first pacing mode switching criteria are met based on the first patient physical activity metric and the actual ventricular rate by:
• setting a threshold rate based on the actual ventricular rate;
• determining a sensor indicated pacing rate based on the first patient physical activity metric;
• and
• determining that the sensor indicated pacing rate is greater than the threshold rate set based on the actual ventricular rate;
• and
• delivering ventricular pacing pulses according to a ventricular lower rate in response to the pacing mode switching criteria being met.

A method, comprising:

• sensing a motion signal;
• determining a first patient physical activity metric from the motion signal;
• determining an actual ventricular rate based on a plurality of ventricular pacing pulses, each of the plurality of ventricular pacing pulses being delivered in response to an atrioventricular pacing interval expiring;
• determining that first pacing mode switching criteria are met based on the first patient physical activity metric and the actual ventricular rate;
• delivering ventricular pacing pulses according to a ventricular lower rate in response to the pacing mode switching criteria being met delivering the ventricular pacing pulses according to the ventricular lower rate for a minimum mode switch time interval;
• determining that the minimum mode switch time interval is expired;
• determining a second patient activity metric from the motion signal;
• after the minimum mode switch time interval is expired, determining that second pacing mode switching criteria are met based on the second patient activity metric;
• and
• switching to an atrioventricular tracking pacing mode in response to the second pacing mode switching criteria being met.

A non-transitory, computer-readable medium storing a set of instructions, which, when executed by a control circuit of a medical device, cause the medical device to:

• sense a motion signal;
• determine a patient physical activity metric from the motion signal;
• determine an actual ventricular rate based on a plurality of ventricular pacing pulses, each of the plurality of ventricular pacing pulses being delivered in response to an atrioventricular pacing interval expiring;
• determine that first pacing mode switching criteria are met based on the first patient physical activity metric and the actual ventricular rate by:
• setting a threshold rate based on the actual ventricular rate;
• determining a sensor indicated pacing rate based on the first patient physical activity metric;
• and
• determining that the sensor indicated pacing rate is greater than the threshold rate set based on the actual ventricular rate;
• and
• deliver ventricular pacing pulses according to a ventricular lower rate in response to the pacing mode switching criteria being met.