Cardioversion energy reduction system

A method of effecting atrial cardioversion between cardioversion electrodes substantially in contact with a patient's atria at a minimal energy comprising the steps of:

• monitoring the cardiac cycle;
• detecting an atrial tachyarrhythmia from the monitored cardiac cycle;
• monitoring the respiratory cycle of the patient;
• detecting a point or phase of the respiratory cycle during which atrial volume is minimized;
• and
• delivering a cardioversion therapy across the cardioversion electrodes in contact with the atria timed to substantially coincide with the detected point or phase of the respiratory cycle.

A method of effecting cardioversion of a heart chamber through the application of a cardioversion shock therapy to cardioversion electrodes implanted in a patient's body comprising the steps of:

• monitoring the patient's cardiac cycle;
• detecting a tachyarrhythmia of the heart chamber from the monitored cardiac cycle;
• monitoring the patient's respiratory cycle;
• timing a therapy time interval for monitoring of the respiratory cycle following detection of the tachyarrhythmia;
• determining an optimum point or phase of the respiratory cycle affecting the volume of the patient's lungs and the impedance between the cardioversion electrodes within the therapy time interval;
• delivering a cardioversion therapy to the cardioversion electrodes timed to substantially fall within the determined optimum point or phase of the respiratory cycle during the therapy time interval;
• and
• delivering a cardioversion therapy to the patient's heart chamber in response to a failure to detect said optimum point or phase of the respiratory cycle.

Apparatus for effecting atrial cardioversion through the application of a cardioversion therapy to cardioversion electrodes implanted in a patient's body comprising:

• means for defining an optimal point or phase of the patients respiratory cycle;
• means for monitoring the patient's cardiac cycle;
• means for detecting an atrial tachyarrhythmia from the monitored cardiac cycle;
• means for monitoring the patient's respiratory cycle;
• means for detecting the optimum point or phase of the respiratory cycle;
• means for detecting ventricular depolarizations;
• means for defining acceptable times for delivery of the cardioversion therapy relative to ventricular depolarizations;
• and
• means for delivering the cardioversion therapy at an acceptable time relative to ventricular depolarizations within the detected optimum point or phase of the respiratory cycle.

A method of effecting cardioversion of a heart chamber, comprising:

• implanting cardioversion electrodes in a patient's body;
• monitoring the patient's cardiac cycle;
• detecting a tacharrhythmia of the heart chamber from the monitored cardiac cycle;
• monitoring the patient's respiratory cycle;
• detecting an optimum point or phase of the respiratory cycle affecting the volume of the patient's lungs and the impedance between the cardioversion electrodes;
• and
• delivering a cardioversion therapy to the cardioversion electrodes timed to substantially fall within the detected optimum point or phase of the respiratory cycle;
• and wherein the step of detecting a point or phase of the respiratory cycle comprises detecting the end of inspiration.

A method of effecting cardioversion of a heart chamber through the application of a cardioversion shock therapy to cardioversion electrodes implanted in a patient's body comprising the steps of:

• monitoring the patient's cardiac cycle;
• detecting a tachyarrhythmia of the heart chamber from the monitored cardiac cycle;
• monitoring the patient's respiratory cycle;
• timing a therapy time interval for monitoring of the respiratory cycle following detection of the tachyarrhythmia;
• determining an optimum point or phase of the respiratory cycle affecting the volume of the patient's lungs and the impedance between the cardioversion electrodes within the therapy time interval;
• delivering a cardioversion therapy to the cardioversion electrodes timed to substantially fall within the determined optimum point or phase of the respiratory cycle during the therapy time interval;
• and
• providing a pre-shock to a cardioversion electrode in response to a failure to detect said optimum point or phase of the respiratory cycle within the therapy time interval for eliciting a respiration cycle through a stimulated contraction of the diaphragm.

Apparatus for effecting atrial cardioversion through the application of a cardioversion therapy to cardioversion electrodes implanted in a patient's body comprising:

• means for defining an optimal point or phase of the patients respiratory cycle;
• means for monitoring the patient's cardiac cycle;
• means for detecting an atrial tachyarrhythmia from the monitored cardiac cycle;
• means for monitoring patient's respiratory cycle;
• means for detecting the optimum point or phase of the respiratory cycle;
• and
• means for delivering a cardioversion therapy to the cardioversion electrodes timed to substantially fall within the detected optimum point or phase of the respiratory cycle;
• and
• wherein the means of detecting a point or phase of the respiratory cycle comprises means for detecting the end of inspiration.

Apparatus for effecting atrial cardioversion between cardioversion electrodes substantially in contact with a patient's atria at a minimal energy comprising:

• means for defining an optimal point or phase of the patient's respiratory cycle;
• means for monitoring the patient's cardiac cycle;
• means for detecting an atrial tachyarrhythmia from the monitored cardiac cycle;
• means for monitoring the respiratory cycle of the patient;
• means for detecting a point or phase of the respiratory cycle;
• means for delivering a cardioversion therapy across the cardioversion electrodes in contact with the atria timed to substantially coincide with the detected point or phase of the respiratory cycle;
• and
• wherein the means of detecting a point or phase of the respiratory cycle further comprises means for determining the end of inspiration.

Apparatus for effecting cardioversion of a heart chamber through the application of a cardioversion shock therapy to cardioversion electrodes implanted in the patient's body comprising:

• means for defining an optimal point or phase of the patient's respiratory cycle;
• means for monitoring the patient's cardiac cycle;
• means for detecting a tachyarrhythmia of the heart chamber from the monitored cardiac cycle;
• means for monitoring the patient's respiratory cycle;
• means for timing a therapy time interval for monitoring of the respiratory cycle following detection of the tachyarrhythmia;
• means for detecting an optimum point or phase of the respiratory cycle affecting the volume of the patient's lungs and the impedance between the cardioversion electrodes within the therapy time interval;
• and
• means for delivering a cardioversion therapy to the cardioversion electrodes timed to substantially fall within the detected optimum point or phase of the respiratory cycle during the therapy time interval;
• and wherein the deliver means for further comprises means for providing a back-up cardioversion therapy to the patient's heart chamber in response to a failure to determine said optimum point or phase of the respiratory cycle within the therapy time interval.

Apparatus for effecting cardioversion of a heart chamber through the application of a cardioversion shock therapy to cardioversion electrodes implanted in the patient's body comprising:

• means for defining an optimal point or phase of the patient's respiratory cycle;
• means for monitoring the patient's cardiac cycle;
• means for detecting a tachyarrhythmia of the heart chamber from the monitored cardiac cycle;
• means for monitoring the patient's respiratory cycle;
• means for timing a therapy time interval for monitoring of the respiratory cycle following detection of the tachyarrhythmia;
• means for detecting an optimum point or phase of the respiratory cycle affecting the volume of the patient's lungs and the impedance between the cardioversion electrodes within the therapy time interval;
• means for delivering a cardioversion therapy to the cardioversion electrodes timed to substantially fall within the detected optimum point or phase of the respiratory cycle during the therapy time interval;
• and
• means for providing a pre-shock to a cardioversion electrode in response to a failure to determine said optimum point or phase of the respiratory cycle within the therapy time interval for eliciting a respiration cycle through a stimulated contraction of the diaphragm.