Implantable stimulation device and method for determining ventricular and atrial sensitivity thresholds

A method of determining ventricular sensitivity threshold in a stimulation device having programmable AV delay, ventricular sensitivity, and post-ventricular refractory period (PVARP), the method comprising:

• automatically determining an optimum AV delay value;
• automatically adjusting the AV delay to the optimum AV delay value;
• lengthening the post-ventricular refractory period (PVARP);
• adjusting the ventricular sensitivity until a ventricular sensitivity threshold is identified;
• setting the ventricular sensitivity to within a safety margin value from the ventricular sensitivity threshold;
• and
• performing an automatic ventricular sensing test using the optimum AV delay value and the ventricular sensitivity setting within the safety margin value.

A stimulation device having a programmable AV delay, comprising:

• a pulse generator;
• sensing circuitry, coupled to the pulse generator, and having a programmable ventricular sensitivity configured to sense R-waves;
• and
• a processor, coupled to the pulse generator and to the sensing circuitry, and programmed to verify intact conduction by detecting the presence of the R-waves in a lengthened AV delay interval, wherein if intact conduction exists, then the processor is programmed to initiate a ventricular sensitivity threshold test using the lengthened AV delay interval, the processor further being programmed to adjust ventricular sensitivity until a threshold value is determined and also to subsequently set the ventricular sensitivity to a safety margin value from the threshold value;
• and
• wherein the processor is programmed to decrease a ventricular rate in the absence of intact conduction.

A stimulation device having a programmable AV delay, comprising:

• a pulse generator;
• sensing circuitry, coupled to the pulse generator, and having a programmable ventricular sensitivity configured to sense R-waves;
• and
• a processor, coupled to the pulse generator and to the sensing circuitry, and programmed to verify intact conduction by detecting the presence of the R-waves in a lengthened AV delay interval, wherein if intact conduction exists, then the processor is programmed to initiate a ventricular sensitivity threshold test using the lengthened AV delay interval, the processor further being programmed to adjust ventricular sensitivity until a threshold value is determined and also to subsequently set the ventricular sensitivity to a safety margin value from the threshold value;
• and
• wherein the processor is programmed to restore the AV delay upon completion of the ventricular sensitivity threshold test.

A stimulation device having a programmable AV delay, comprising:

• a pulse generator;
• sensing circuitry, coupled to the pulse generator, and having a programmable ventricular sensitivity configured to sense R-waves;
• a processor, coupled to the pulse generator and to the sensing circuitry, and programmed to verify intact conduction by detecting the presence of the R-waves in a lengthened AV delay interval, wherein if intact conduction exists, then the processor is programmed to initiate a ventricular sensitivity threshold test using the lengthened AV delay interval, the processor further being programmed to adjust ventricular sensitivity until a threshold value is determined and also to subsequently set the ventricular sensitivity to a safety margin value above the threshold value;
• wherein the device further comprises a timing circuitry, coupled to the processor, and configured to control the AV delay and a post-ventricular refractory period (PVARP);
• wherein the processor is further programmed to automatically lengthen the post-ventricular refractory period (PVARP) during the sensitivity threshold test to reduce the possibility of premature and retrograde P-waves.

A programmer for determining ventricular sensitivity threshold in a stimulation device having programmable AV delay, ventricular sensitivity, and post-ventricular refractory period (PVARP), the programmer comprising:

• sensing circuitry for automatically determining an optimum AV delay value;
• a processor connected to said sensing circuitry for causing the AV delay to be automatically adjusted to the optimum AV delay value and for the post-ventricular refractory period (PVARP) to be lengthened;
• the processor causing the ventricular sensitivity to be adjusted until a ventricular sensitivity threshold is identified, and the ventricular sensitivity to be set within a safety margin value from the ventricular sensitivity threshold;
• and
• the processor performing an automatic ventricular threshold sensing test using the optimum AV delay value and the ventricular sensitivity setting within the safety margin value.

A method of determining ventricular sensitivity threshold in a stimulation device having programmable AV delay and ventricular sensitivity, the method comprising:

• automatically determining an optimum AV delay value;
• automatically adjusting the AV delay to the optimum AV delay value;
• adjusting the ventricular sensitivity until a ventricular sensitivity threshold is identified;
• setting the ventricular sensitivity to a prescribed safety margin value above the ventricular sensitivity threshold;
• and
• performing a sensing test using the optimum AV delay value.

A method for determining a ventricular sensitivity in a stimulation device having an adjustable ventricular sensitivity, the method comprising:

• setting the stimulation device to an atrial tracking mode, if the stimulation device is operating in a non-atrial tracking mode;
• assessing ventricular sensing of the stimulation device;
• if ventricular sensing is confirmed, performing a ventricular sensitivity threshold test to determine a ventricular sensitivity threshold of the stimulation device;
• and
• automatically adjusting the ventricular sensitivity to within a safety margin from the ventricular sensitivity threshold.

A programmer for determining a ventricular sensitivity in a stimulation device having an adjustable ventricular sensitivity, the programmer comprising:

• a processor for setting the stimulation device to an atrial tracking mode if the stimulation device is operating in a non-atrial tracking mode;
• the processor assessing ventricular sensing of the stimulation device;
• if ventricular sensing is confirmed, the processor performing a ventricular sensitivity threshold test to determine the ventricular sensitivity threshold of the stimulation device;
• and
• the processor automatically adjusting the ventricular sensitivity to within a safety margin from the ventricular sensitivity threshold.

A method for determining an atrial sensitivity in a stimulation device having adjustable base rate and atrial sensitivity, the method comprising:

• setting the stimulation device to an atrial tracking mode, if the stimulation device is operating in a non-atrial tracking mode;
• assessing atrial sensing of the stimulation device and determining a sensed atrial rate;
• if atrial sensing is confirmed, determining whether the base rate is less than the sensed atrial rate by at least a predetermined value;
• if the base rate is less than the sensed atrial rate by at least the predetermined value, then performing an atrial sensitivity threshold test to determine an atrial sensitivity threshold of the stimulation device;
• and
• automatically adjusting the atrial sensitivity to within a safety margin from the atrial sensitivity threshold.

A programmer for determining an atrial sensitivity in a stimulation device having adjustable base rate and atrial sensitivity, the programmer comprising:

• a processor for setting the stimulation device to an atrial tracking mode if the stimulation device is operating in a non-atrial tracking mode;
• the processor assessing atrial sensing of the stimulation device;
• if atrial sensing is confirmed, the programmer determining whether the base rate is less than the sensed atrial rate by at least a predetermined value;
• if the base rate is less than the sensed atrial rate by at least the predetermined value, the processor performing an atrial sensitivity threshold test to determine the atrial sensitivity threshold of the stimulation device;
• and
• the processor automatically adjusting the atrial sensitivity to within a safety margin from the atrial sensitivity threshold.