Systems and methods for determining an optimal defibrillation shock waveform

A method for determining an optimal defibrillation shock waveform for application to the heart of a patient by an implanted defibrillation system comprising:

• measuring and/or collecting information for a cardiac waveform of a patient, produced as a result of either an electrical stimulus applied to a heart of the patient or as the result of intrinsic cardiac activation, wherein the cardiac waveform is a cardiac electrogram of the patient corresponding to at least one complete heart cycle, wherein the cardiac electrogram is a measure of the varying electrical potential between two electrodes positioned adjacent the heart and is characterized by a baseline, at least one peak above the baseline, and at least one trough below the baseline;
• determining at least one characteristic of the electrogram;
• comparing the determined characteristic(s) of the cardiac electrogram to a plurality of values for the characteristic, wherein each value of the characteristic is associated with a predetermined value for a parameter of an optimal defibrillation shock waveform with optional reference to the defibrillator system impedance;
• and
• selecting the predetermined value for the parameter of the optimal defibrillation shock waveform for subsequent delivery by the implanted defibrillation system, wherein the parameter is selected based on the comparison;
• wherein the at least one parameter defines the optimal defibrillation shock waveform and is selected from a group consisting of:
• a total energy of an optimal defibrillation shock waveform, a voltage of an optimal defibrillation shock waveform, a current of an optimal defibrillation shock waveform, a time period for a first phase of an optimal defibrillation shock waveform, a time period for second phase of an optimal defibrillation shock waveform for the patient, a time period for a third phase of a defibrillator shock waveform, a tilt of an optimal defibrillation shock waveform, and a polarity of a phase of a defibrillator shock waveform.

A system for determining an optimal defibrillation shock waveform for application to the heart of a patient by an implanted defibrillation system, said system comprising:

• means for obtaining a cardiac electrogram of the patient corresponding to at least one complete heart cycle, wherein the cardiac electrogram is a measure of the varying electrical potential between two electrodes positioned adjacent the heart and is characterized by a baseline, at least one peak above the baseline, and at least one trough below the baseline;
• determining means for determining a value of at least one characteristic of the cardiac electrogram;
• and
• selecting means for selecting a predetermined value for at least one parameter of an optimal defibrillation shock waveform for subsequent delivery by the implanted defibrillation system, wherein the at least one parameter is based on the determined value of the at least one characteristic of the cardiac electrogram with optional reference to the defibrillator system impedance;
• wherein the at least one parameter defines the optimal defibrillation shock waveform and is selected from a group consisting of:
• a total energy of an optimal defibrillation shock waveform, a voltage of an optimal defibrillation shock waveform, a current of an optimal defibrillation shock waveform, a time period for a first phase of an optimal defibrillation shock waveform, a time period for second phase of an optimal defibrillation shock waveform for the patient, a time period for a third phase of a defibrillator shock waveform, a tilt of an optimal defibrillation shock waveform, and a polarity of a phase of a defibrillator shock waveform.

A system for determining an optimal defibrillation shock waveform for application to the heart of a patient by an implanted defibrillation system, said system comprising:

• measuring and/or collecting means for measuring and/or collecting, respectively, information for a cardiac waveform of a patient, produced as a result of either an electrical stimulus applied to a heart of the patient, which may be a pacing shock and/or a defibrillation shock waveform, or as the result of intrinsic cardiac activation, wherein the cardiac waveform is a cardiac electrogram of the patient corresponding to at least one complete heart cycle, wherein the cardiac electrogram is a measure of the varying electrical potential between two electrodes positioned adjacent the heart and is characterized by a baseline, at least one peak above the baseline, and at least one trough below the baseline;
• determining means for determining a characteristic of the electrogram;
• comparing means for comparing the determined characteristic of the cardiac electrogram to a plurality of first values for the characteristic, wherein each first value of the characteristic is associated with a predetermined value for a parameter of an optimal defibrillation shock waveform;
• and
• selecting means for selecting the predetermined value for the parameter of the optimal defibrillation shock waveform for subsequent delivery by the implanted defibrillation system, wherein the parameter is selected based on the comparison;
• wherein the at least one parameter defines the optimal defibrillation shock waveform and is selected from a group consisting of:
• a total energy of an optimal defibrillation shock waveform, a voltage of an optimal defibrillation shock waveform, a current of an optimal defibrillation shock waveform, a time period for a first phase of an optimal defibrillation shock waveform, a time period for second phase of an optimal defibrillation shock waveform for the patient, a time period for a third phase of a defibrillator shock waveform, a tilt of an optimal defibrillation shock waveform, and a polarity of a phase of a defibrillator shock waveform.

A method for determining an optimal defibrillation shock waveform for an implanted defibrillation device, the method comprising:

• measuring and/or collecting information of a cardiac waveform of a patient produced as a result of either an electrical stimulus applied to a heart of the patient or as the result of intrinsic cardiac activation, wherein the cardiac waveform is a cardiac electrogram of the patient corresponding to at least one complete heart cycle, wherein the cardiac electrogram is a measure of the varying electrical potential between two electrodes positioned adjacent the heart and is characterized by a baseline, at least one peak above the baseline, and at least one trough below the baseline;
• determining at least one characteristic of the electrogram;
• and
• using the characteristic or combination of characteristics to calculate at least one value for a parameter of an optimal defibrillation shock waveform for subsequent delivery by the implanted defibrillation device, wherein the at least one parameter is far the patient with optional reference to the defibrillator system impedance;
• wherein the at least one parameter defines the optimal defibrillation shock waveform and is selected from a group consisting of:
• a total energy of an optimal defibrillation shock waveform, a voltage of an optimal defibrillation shock waveform, a current of an optimal defibrillation shock waveform, a time period for a first phase of an optimal defibrillation shock waveform, a time period for second phase of an optimal defibrillation shock waveform for the patient, a time period for a third phase of a defibrillator shock waveform, a tilt of an optimal defibrillation shock waveform, and a polarity of a phase of a defibrillator shock waveform.