Implantable cardiac stimulation device and method for optimizing sensing performance during rate adaptive bradycardia pacing

An implantable cardiac stimulation device including a ventricular defibrillator and a cardiac pacer comprising:

• a pulse generator that applies stimulation pulses to a heart at a variable stimulation rate;
• a sensing circuit that senses ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters;
• a processor that adjusts the post-stimulation sensing parameters responsive to a calculated stimulation rate;
• and
• wherein the sensing circuit has an initial sensing threshold, wherein the initial sensing threshold is one of the post-stimulation sensing parameters and wherein the processor adjusts the initial sensing threshold responsive to the calculated stimulation rate.

In an implantable stimulation device including a ventricular defibrillator and a rate adaptive cardiac pacer, a method of applying stimulation pulses to a heart and sensing ventricular activity after applying a stimulation pulse including the steps of:

• applying stimulation pulses to a heart at a stimulation rate that varies as a function of physiologic demand;
• sensing ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters;
• and
• adjusting one of the post-stimulation sensing parameters comprising an initial sensing threshold responsive to a calculated stimulation rate.

An implantable cardiac stimulation device including a ventricular defibrillator and a rate adaptive cardiac pacer comprising:

• pulse generating means for applying stimulation pulses to a patient's heart at a variable stimulation rate that is a function of a sensed physiologic demand;
• sensing means for sensing ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters including a decreasing sensing threshold which begins decreasing a delay time after application of a stimulation pulse;
• and
• adjusting means for adjusting the delay time responsive to the calculated stimulation rate.

An implantable cardiac stimulation device including a ventricular defibrillator and a cardiac pacer comprising:

• a pulse generator that applies stimulation pulses to a heart at a variable stimulation rate;
• a sensing circuit that senses ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters;
• a processor that adjusts the post-stimulation sensing parameters responsive to a calculated stimulation rate;
• and
• wherein the sensing circuit has a decreasing sensing threshold which begins decreasing a delay time after application of a stimulation pulse, wherein the delay time is one of the post-stimulation sensing parameters, and wherein the process adjusts the delay time responsive to the calculated stimulation rate.

In an implantable stimulation device including a ventricular defibrillator and a rate adaptive cardiac pacer, a method of applying stimulation pulses to a heart and sensing ventricular activity after applying a stimulation pulse including the steps of:

• applying stimulation pulses to a heart at a stimulation rate that varies as a function of physiologic demand;
• sensing ventricular activity of the heart by setting a sensing threshold and decreasing the sensing threshold a delay time after applying a stimulation pulse;
• and
• adjusting the delay time responsive to a calculated stimulation rate.