Apparatus and method for detecting abnormal cardiac rhythms using an ultrasound sensor in an arrhythmia control system

A dual chamber antitachycardia pacing device for the reversion of tachycardias comprising:

• means for generating atrial and ventricular stimulation pulses and adapted to deliver said pulses to a patient's atrium and ventricle, respectively,
• ultrasonic means adapted to be implanted within the patient's cardiovascular system for monitoring a cardiac output parameter corresponding to the volume of blood flow per unit of time within the cardiovascular system,
• means for deriving a cardiac output standard based on a time history of said cardiac output parameter,
• means for determining the patient's heart rate,
• analyzing means for comparing said cardiac output parameter to said cardiac output standard and for comparing said heart rate to a predetermined heart rate boundary,
• means responsive to the detection of a pathological tachycardia by said analyzing means for detecting a pathological tachycardia when said cardiac output parameter is less than a predetermined percentage of said cardiac output standard and said heart rate is faster than said predetermined heart rate boundary, and
• means responsive to the detection of a pathological tachycardia by said detecting means for controlling said generating means to operate in an antitachycardia pacing mode.

A method of detecting and reverting cardiac arrhythmias in an antiarrhythmia pacing device comprising the steps of:

• activating an ultrasonic sensor implanted within a patient's cardiovascular system,
• monitoring the output of said ultrasonic sensor to provide a cardiac output parameter corresponding to the volume of blood flow per unit of time within the cardiovascular system,
• deriving a cardiac output standard based on a time history of said cardiac output parameters,
• comparing said cardiac output parameter to said cardiac output standard,
• detecting and classifying at least one pathological arrhythmia condition when said cardiac output parameter is less than at least one predetermined percentage of said cardiac output standard,
• generating stimulation pulses for delivery within the patient's heart, and
• controlling the timing and sequence of said pulse stimulations to operate in an antiarrhythmia pacing mode corresponding to said classification.

A method of detecting and reverting cardiac arrhythmias in a dual chamber antitachycardia pacing device comprising the steps of:

• activating an ultrasonic sensor implanted within a patient's cardiovascular system,
• monitoring the output of said ultrasonic sensor to provide a cardiac output parameter corresponding to the volume of blood flow per unit of time within the cardiovascular system,
• deriving a cardiac output standard based on a time history of said cardiac output parameters,
• determining the patient's heart rate,
• comparing said cardiac output parameter to said cardiac output standard and comparing said heart rate to a predetermined heart rate boundary,
• detecting a pathological arrhythmia when said cardiac output parameter is less than a predetermined percentage of said cardiac output standard and said heart rate is faster than said predetermined heart rate boundary,
• generating stimulation pulses for delivery within the patient's atrium and ventricle, and
• controlling the timing and sequence of said atrial and ventricular pulse stimulations to operate in an antiarrhythmia pacing mode.

An antiarrhythmia pacing device for the reversion of cardiac arrhythmias comprising:

• means for generating stimulation pulses and adapted to deliver said pulses to a patient's heart,
• ultrasonic means adapted to be implanted within the patient's right heart for ensonifying the patient's ascending aorta with ultrasonic energy and detecting returning ultrasonic energy reflected from blood cells within the ascending aorta for monitoring a cardiac output parameter corresponding to the volume of blood flow per unit of time within the cardiovascular system,
• means for deriving a cardiac output standard based on a time history of said cardiac output parameter,
• means for comparing said cardiac output parameter to said cardiac output standard,
• means responsive to said comparing means for detecting and classifying a pathological cardiac arrhythmia when said cardiac output parameter is less than at least one predetermined percentage of said cardiac output standard, and
• means responsive to said detecting means for controlling said generating means to operate in an antiarrhythmia pacing mode corresponding to said classification.

A method of detecting and reverting cardiac arrhythmias in an antiarrhythmia pacing device comprising the steps of:

• activating an ultrasonic sensor implanted within a patient's right heart, wherein said activating step includes the sub-steps of ensonifying the patient's ascending aorta with ultrasonic energy, and detecting returning ultrasonic energy reflected from blood cells within the ascending aorta,
• monitoring the output of said ultrasonic sensor to provide a cardiac output parameter corresponding to the volume of blood flow per unit of time within the cardiovascular system,
• deriving a cardiac output standard based on a time history of said cardiac output parameters,
• comparing said cardiac output parameter to said cardiac output standard,
• detecting and classifying at least one pathological arrthythmia condition when said cardiac output parameter is less than at least one predetermined percentage of said cardiac output standard,
• generating stimulation pulses for delivery within the patient's heart, and
• controlling the timing and sequence of said pulse stimulations to operate in an antiarrhythmia pacing mode corresponding to said classification.