Method and device for responding to the detection of ischemia in cardiac tissue

A method of treating ischemia of patient's heart using an implantable cardiac stimulation device operating according to a set of prescribed adaptable pacing parameters including a pacing rate set as a function of the patient's activity level up to a maximum sensor rate and an aggressiveness value specifying the rate of increase of the pacing rate per the increase in the patient's activity level, wherein each of the parameters has an original value in the absence of ischemia, the method comprising the steps of:

• detecting the presence of ischemia in the patient's heart;
• incrementally altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified amount, initially from its respective original value, in response to detecting the presence of ischemia in the patient's heart;
• and
• incrementally altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device back toward its original value in response to not detecting the presence of ischemia in the patient's heart for a prescribed time period.

An implantable cardiac stimulation device configured for stimulating a patient's heart through at least one electrode implanted in electrical contact with selected cardiac tissue, the cardiac stimulation device comprising:

• at least one pulse generator configured for electrical coupling to the at least one electrode and configured to generate stimulation pulses at a pacing rate according to a set of prescribed adaptable pacing parameters, wherein each parameter has an original value in the absence of ischemia;
• an ischemia detector configured for determining the presence of ischemia in at least a portion of the cardiac tissue;
• a controller, coupled to the ischemia detector for periodically altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified incremental amount, initially from its respective original value, in response to detecting the presence of ischemia by the ischemia detector;
• wherein
• the controller additionally alters at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device in response to the ischemia detector not detecting the presence of ischemia for a prescribed period.

An implantable cardiac stimulation device configured for stimulating a patient's heart through at least one electrode implanted in electrical contact with selected cardiac tissue, the cardiac stimulation device comprising:

• at least one pulse generator configured for electrical coupling to the at least one electrode and configured to generate stimulation pulses at a pacing rate according to a set of prescribed adaptable pacing parameters, wherein each parameter has an original value in the absence of ischemia;
• an ischemia detector configured for determining the presence of ischemia in at least a portion of the cardiac tissue;
• a controller, coupled to the ischemia detector for periodically altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified incremental amount, initially from its respective original value, in response to detecting the presence of ischemia by the ischemia detector;
• wherein the at least one electrode includes an electrode in electrical contact with an atrium of the patient's heart and an electrode in electrical contact with a ventricle of the patient's heart and the at least one pulse generator includes an atrial pulse generator and a ventricular pulse generator to respectively generate atrial and ventricular stimulation pulses to the atrium and ventricle of the patient's heart;
• and wherein
• the prescribed adaptable pacing parameters include an AV delay defining the delay between delivery of an atrial stimulation pulse and delivery of a ventricular stimulation pulse by the cardiac stimulation device and the controller increases the AV delay by a prescribed amount in response to the ischemia detector detecting the presence of ischemia.

An implantable cardiac stimulation device configured for stimulating a patient's heart through at least one electrode implanted in electrical contact with selected cardiac tissue, the cardiac stimulation device comprising:

• at least one pulse generator configured for electrical coupling to the at least one electrode and configured to generate stimulation pulses at a pacing rate according to a set of prescribed adaptable pacing parameters, wherein each parameter has an original value in the absence of ischemia;
• an ischemia detector configured for determining the presence of ischemia in at least a portion of the cardiac tissue;
• a controller, coupled to the ischemia detector for periodically altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified incremental amount, initially from its respective original value, in response to detecting the presence of ischemia by the ischemia detector;
• wherein the at least one electrode includes an electrode in electrical contact with an atrium of the patient's heart and an electrode in electrical contact with a ventricle of the patient's heart and the at least one pulse generator is configured to deliver ventricular stimulation pulses to the ventricle of the patient's heart, the cardiac stimulation device additional comprising:
• a sensing circuit configured to receive a signal from the electrode in electrical contact with the atrium of the patient's heart for detecting intrinsic P-waves from the patient's heart;
• and wherein
• the pacing parameters additionally include a PV delay defining the delay between a sensed P-wave and delivery of a ventricular stimulation pulse by the cardiac stimulation device and the controller increases the PV delay by a specified amount in response to the ischemia detector detecting the presence of ischemia.

An implantable cardiac stimulation device configured for stimulating a patient's heart through at least one electrode implanted in electrical contact with selected cardiac tissue, the cardiac stimulation device comprising:

• at least one pulse generator configured for electrical coupling to the at least one electrode and configured to generate stimulation pulses at a pacing rate according to a set of prescribed adaptable pacing parameters, wherein each parameter has an original value in the absence of ischemia;
• an ischemia detector configured for determining the presence of ischemia in at least a portion of the cardiac tissue;
• a controller, coupled to the ischemia detector for periodically altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified incremental amount, initially from its respective original value, in response to detecting the presence of ischemia by the ischemia detector;
• wherein the controller continues to periodically incrementally alter at least one of the prescribed adaptable pacing parameters by the specified amount while ischemia is still detected by the ischemia detector and wherein the controller is operative to incrementally alter the at least one of the prescribed adaptable pacing parameters back toward its original value in response to not detecting the presence of ischemia by the ischemia detector for a prescribed period of time.

An implantable cardiac stimulation device configured for stimulating a patient's heart through at least one electrode implanted in electrical contact with selected cardiac tissue, the cardiac stimulation device comprising:

• at least one pulse generator configured for electrical coupling to the at least one electrode and configured to generate stimulation pulses at a pacing rate according to a set of prescribed adaptable pacing parameters, wherein each parameter has an original value in the absence of ischemia;
• an ischemia detector configured for determining the presence of ischemia in at least a portion of the cardiac tissue;
• a controller, coupled to the ischemia detector for periodically altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified incremental amount, initially from its respective original value, in response to detecting the presence of ischemia by the ischemia detector;
• an activity sensor for determining the patients activity level;
• a controller, coupled to the pulse generator and the activity sensor for determining the pacing rate as a function of the determined patient's activity level up to a maximum sensor rate and according to a rate response aggressiveness value specifying the rate of increase of the pacing rate per the increase in the patient's activity level, wherein the prescribed adaptable pacing parameters include the maximum sensor rate and the rate response aggressiveness values;
• and wherein
• the controller is configured to incrementally alter at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified amount from its respective original value in response to detecting the presence of ischemia by the ischemia detector;
• wherein the controller incrementally decreases the rate response aggressiveness in response to ischemia being detected by the ischemia detector.

An implantable cardiac stimulation device configured for stimulating a patients heart through at least one electrode implanted in electrical contact with selected cardiac tissue, the cardiac stimulation device comprising:

• means for generating and delivering stimulation pulses to the at least one electrode according to a set of prescribed adaptable pacing parameters, wherein each pacing parameter has an original value in the absence of ischemia;
• means for detecting the presence of ischemia in at least a portion of the cardiac tissue;
• and
• means for periodically altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified incremental amount, from its respective original value, in response to detecting the presence of ischemia by the ischemia detecting means
• wherein at least one of the prescribed adaptable pacing parameters is incrementally altered to minimize the presence of ischemia in response to detecting the presence of ischemia by the ischemia detecting means;
• wherein the altered pacing parameter is incrementally altered back toward its original value in response to not detecting the presence of ischemia by the ischemia detecting means for a prescribed period of time.

A method of treating ischemia of a patient's heart using an implantable cardiac stimulation device operating according to a set of one or more prescribed adaptable pacing parameters including at least a pacing rate set as a function of the patient's activity level up to a maximum sensor rate, wherein each of the parameters has an original value in the absence of ischemia, the method comprising the steps of:

• detecting the presence of ischemia in the patient's heart;
• determining the pacing rate when ischemia is detected;
• altering the maximum sensor rate according to the pacing rate when ischemia is detected;
• incrementally altering at least one of the prescribed adaptable pacing parameters of the cardiac stimulation device by a specified amount in response to continuing to detect the presence of ischemia in the patient's heart.