Rate management during automatic capture verification

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) a pulse generator that generates stimulation pulses;
• (b) a controller having a timing circuit, sensing circuit and stimulation circuit for controlling activation of the pulse generator and delivery of the stimulation pulses;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said controller, wherein electrocardiogram signals are electrically conducted to said controller, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold;
• and
• (e) wherein said sensing circuit includes a sense amplifier electrically connected to the electrodes and controller in a manner wherein a polarity of an amplitude of the electrocardiogram signal corresponding to an evoked response is opposite a polarity of an amplitude of the electrocardiogram signal corresponding to afterpotential.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) a pulse generator that generates stimulation pulses;
• (b) a controller having a timing circuit, sensing circuit and stimulation circuit for controlling activation of the pulse generator and delivery of the stimulation pulses;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said controller, wherein electrocardiogram signals are electrically conducted to said controller, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold;
• (e) wherein said stimulation circuit includes a coupling capacitor arrangement that reduces afterpotentials;
• and
• (f) wherein said coupling capacitor arrangement includes a capacitor having a capacitance less than 5 microfarads.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) a pulse generator that generates stimulation pulses;
• (b) a controller having a timing circuit, sensing circuit and stimulation circuit for controlling activation of the pulse generator and delivery of the stimulation pulses;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said controller, wherein electrocardiogram signals are electrically conducted to said controller, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold;
• and
• (e) wherein the sensing circuit includes a pre-amplifier electrically coupled to the electrodes, a first high pass coupling capacitor electrically coupled between the electrodes and said pre-amplifier, and a blanking switch electrically coupled between said high pass coupling capacitor and said pre-amplifier, said sensing circuit further including a dedicated evoked response amplifier.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) a pulse generator that generates stimulation pulses;
• (b) a controller having a timing circuit, sensing circuit and stimulation circuit for controlling activation of the pulse generator and delivery of the stimulation pulses;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said controller, wherein electrocardiogram signals are electrically conducted to said controller, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold;
• (e) wherein the sensing circuit includes an afterpotential attenuation system for attenuating afterpotentials which result due to delivery of the stimulation pulses;
• and
• (f) wherein said afterpotential attenuation means includes a first coupling capacitor operatively coupled to a second coupling capacitor, and a switching system for selectively coupling said second coupling capacitor in series with said first coupling capacitor so as to reduce the effective capacitance of said first and second coupling capacitor.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) a pulse generator that generates stimulation pulses;
• (b) a controller having a timing circuit, sensing circuit and stimulation circuit for controlling activation of the pulse generator and delivery of the stimulation pulses;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said controller, wherein electrocardiogram signals are electrically conducted to said controller, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold, said sensing circuit including a sense amplifier electrically connected to the electrodes and controller in a manner wherein a polarity of an amplitude of the electrocardiogram signal corresponding to an evoked response is opposite a polarity of an amplitude of the electrocardiogram signal corresponding to afterpotential;
• and
• (e) wherein said controller detects an evoked response of the patient's heart from the electrocardiogram signal, determines an amplitude associated with the evoked response, and adjusts the detection threshold dependent upon the determined amplitude.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) a pulse generator that generates stimulation pulses;
• (b) a controller having a timing circuit, sensing circuit and stimulation circuit for controlling activation of the pulse generator and delivery of the stimulation pulses;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said controller, wherein electrocardiogram signals are electrically conducted to said controller, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold, said sensing circuit including a sense amplifier electrically connected to the electrodes and controller in a manner wherein a polarity of an amplitude of the electrocardiogram signal corresponding to an evoked response is opposite a polarity of an amplitude of the electrocardiogram signal corresponding to afterpotential;
• and
• (e) wherein said stimulation circuit includes a coupling capacitor arrangement that reduces afterpotentials;
• and
• (f) wherein said coupling capacitor arrangement includes a capacitor having a capacitance less than 5 microfarads.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) a pulse generator that generates stimulation pulses;
• (b) a controller having a timing circuit, sensing circuit and stimulation circuit for controlling activation of the pulse generator and delivery of the stimulation pulses;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said controller, wherein electrocardiogram signals are electrically conducted to said controller, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold, said sensing circuit including a sense amplifier electrically connected to the electrodes and controller in a manner wherein a polarity of an amplitude of the electrocardiogram signal corresponding to an evoked response is opposite a polarity of an amplitude of the electrocardiogram signal corresponding to afterpotential;
• and
• (e) wherein the sensing circuit includes an afterpotential attenuation system for attenuating afterpotentials which result due to delivery of the stimulation pulses;
• and
• (f) wherein said afterpotential attenuation means includes a first coupling capacitor operatively coupled to a second coupling capacitor, and a switching device for selectively coupling said second coupling capacitor in series with said first coupling capacitor so as to reduce the effective capacitance of said first and second coupling capacitor.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's her, said rhythm management device including:

• (a) a pulse generator that generates stimulation pulses;
• (b) a controller having a timing circuit, sensing circuit and stimulation circuit for controlling activation of the pulse generator and delivery of the stimulation pulses;
• (c) electrodes positioned within a patient's heart and electrically coupled to said controller, wherein electrocardiogram signals are electrically conducted to said controller, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold, said sensing circuit including a sense amplifier electrically connected to the electrodes and controller in a manner wherein a polarity of an amplitude of the electrocardiogram signal corresponding to an evoked response is opposite a polarity of an amplitude of the electrocardiogram signal corresponding to afterpotential;
• (e) wherein said controller detects the presence of noise in the electrocardiogram signal;
• and
• (f) wherein said controller determines a value associated with an amplitude of the detected noise.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) means for generating stimulation pulses;
• (b) control means for controlling activation of said means for generating stimulation pulses and for controlling delivery of stimulation pulses, said control means having a timing circuit, sensing circuit and stimulation circuit;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said control means such that electrocardiogram signals are electrically conducted to said control means, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise, said control means determines a value associated with an amplitude of the detected noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold, wherein said control means adjusts the detection threshold dependant upon the value associated with the amplitude of the detected noise;
• and
• (e) wherein said control means detects an evoked response of the patient's heart from the electrocardiogram signal, determines an amplitude associated with the evoked response, and further adjusts the detection threshold dependent upon the determined amplitude.

An implantable cardiac rhythm management device capable of automatically detecting intrinsic and evoked response of a patient's heart, said rhythm management device including:

• (a) means for generating stimulation pulses;
• (b) control means for controlling activation of said means for generating stimulation pulses and for controlling delivery of stimulation pulses, said control means having a timing circuit, sensing circuit and stimulation circuit;
• (c) electrodes for positioning within a patient's heart and electrically coupled to said control means such that electrocardiogram signals are electrically conducted to said control means, said electrocardiogram signal including electrical impulses corresponding to a cardiac depolarization and noise, said control means determines a value associated with an amplitude of the detected noise;
• (d) said sensing circuit coupled to said timing circuit and including an adjustable detection threshold, wherein said control means adjusts the detection threshold dependant upon the value associated with the amplitude of the detected noise;
• and
• (e) memory means for storing the determined value associated with an amplitude of noise over a plurality of detected cardiac depolarization, wherein the control means adjusts the sensing threshold dependant upon the determined value associated with an amplitude of noise corresponding to prior detected cardiac depolarization.